diff --git a/src/checksum.c b/src/checksum.c
index 34291cb2..abca0332 100644
--- a/src/checksum.c
+++ b/src/checksum.c
@@ -1064,9 +1064,10 @@ INT_PTR CALLBACK ChecksumCallback(HWND hDlg, UINT message, WPARAM wParam, LPARAM
 
 		safe_release_dc(GetDlgItem(hDlg, IDC_MD5), hDC);
 
-		for (i=(int)safe_strlen(image_path); (i>0)&&(image_path[i]!='\\'); i--);
-		if (image_path != NULL)	// VS code analysis has a false positive on this one
-			SetWindowTextU(hDlg, &image_path[i+1]);
+		if (image_path != NULL) {
+			for (i = (int)strlen(image_path); (i > 0) && (image_path[i] != '\\'); i--);
+			SetWindowTextU(hDlg, &image_path[i + 1]);
+		}
 		// Set focus on the OK button
 		SendMessage(hDlg, WM_NEXTDLGCTL, (WPARAM)GetDlgItem(hDlg, IDOK), TRUE);
 		CenterDialog(hDlg, NULL);
diff --git a/src/dev.c b/src/dev.c
index fb4c45b7..1be9b32f 100644
--- a/src/dev.c
+++ b/src/dev.c
@@ -655,6 +655,7 @@ BOOL GetDevices(DWORD devnum)
 				}
 				// Also test for "_SD&" instead of "_SD_" and so on to allow for devices like
 				// "SCSI\DiskRicoh_Storage_SD&REV_3.0" to be detected.
+				assert(strlen(scsi_card_name_copy) > 1);
 				scsi_card_name_copy[strlen(scsi_card_name_copy) - 1] = '&';
 				if (safe_strstr(buffer, scsi_card_name_copy) != NULL) {
 					props.is_CARD = TRUE;
@@ -668,7 +669,7 @@ BOOL GetDevices(DWORD devnum)
 		if (!SetupDiGetDeviceInstanceIdA(dev_info, &dev_info_data, device_instance_id,
 			sizeof(device_instance_id), &size)) {
 			uprintf("SetupDiGetDeviceInstanceId failed: %s", WindowsErrorString());
-			static_strcpy(device_instance_id, "<N/A>");
+			strcpy(device_instance_id, "<N/A>");
 		}
 
 		memset(buffer, 0, sizeof(buffer));
diff --git a/src/dos_locale.c b/src/dos_locale.c
index 98730081..8a4dace9 100644
--- a/src/dos_locale.c
+++ b/src/dos_locale.c
@@ -1,7 +1,7 @@
 /*
  * Rufus: The Reliable USB Formatting Utility
  * DOS keyboard locale setup
- * Copyright © 2011-2020 Pete Batard <pete@akeo.ie>
+ * Copyright © 2011-2021 Pete Batard <pete@akeo.ie>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -982,6 +982,7 @@ BOOL SetDOSLocale(const char* path, BOOL bFreeDOS)
 		kb = "us";
 		kbdrv = bFreeDOS?fd_get_kbdrv(kb):ms_get_kbdrv(kb);	// Always succeeds
 	}
+	assert(kbdrv >= 0);
 	uprintf("Will use DOS keyboard '%s' [%s]\n", kb, kb_to_hr(kb));
 
 	// Now get a codepage
diff --git a/src/ext2fs/alloc.c b/src/ext2fs/alloc.c
index ea573efb..69baf14c 100644
--- a/src/ext2fs/alloc.c
+++ b/src/ext2fs/alloc.c
@@ -301,8 +301,8 @@ errcode_t ext2fs_get_free_blocks2(ext2_filsys fs, blk64_t start, blk64_t finish,
 	if (!num)
 		num = 1;
 	c_ratio = 1 << ext2fs_get_bitmap_granularity(map);
-	b &= ~(c_ratio - 1);
-	finish &= ~(c_ratio -1);
+	b &= ~((blk64_t)c_ratio - 1);
+	finish &= ~((blk64_t)c_ratio - 1);
 	do {
 		if (b + num - 1 >= ext2fs_blocks_count(fs->super)) {
 			if (finish > start)
diff --git a/src/ext2fs/ext_attr.c b/src/ext2fs/ext_attr.c
index affc1a8f..0d794ea6 100644
--- a/src/ext2fs/ext_attr.c
+++ b/src/ext2fs/ext_attr.c
@@ -1438,7 +1438,7 @@ static errcode_t xattr_array_update(struct ext2_xattr_handle *h,
 		return 0;
 	}
 
-	if (h->ibody_count <= old_idx) {
+	if (old_idx >= 0 && h->ibody_count <= old_idx) {
 		block_free += EXT2_EXT_ATTR_LEN(name_len);
 		if (!h->attrs[old_idx].ea_ino)
 			block_free +=
diff --git a/src/ext2fs/fileio.c b/src/ext2fs/fileio.c
index a0b5d971..cac97af8 100644
--- a/src/ext2fs/fileio.c
+++ b/src/ext2fs/fileio.c
@@ -357,13 +357,8 @@ ext2fs_file_write_inline_data(ext2_file_t file, const void *buf,
 		file->pos += count;
 
 		/* Update inode size */
-		if (count != 0 && EXT2_I_SIZE(&file->inode) < file->pos) {
-			errcode_t	rc;
-
-			rc = ext2fs_file_set_size2(file, file->pos);
-			if (retval == 0)
-				retval = rc;
-		}
+		if (count != 0 && EXT2_I_SIZE(&file->inode) < file->pos)
+			retval = ext2fs_file_set_size2(file, file->pos);
 
 		if (written)
 			*written = count;
diff --git a/src/ext2fs/gen_bitmap.c b/src/ext2fs/gen_bitmap.c
index c94c21b6..542d17a9 100644
--- a/src/ext2fs/gen_bitmap.c
+++ b/src/ext2fs/gen_bitmap.c
@@ -117,7 +117,7 @@ errcode_t ext2fs_make_generic_bitmap(errcode_t magic, ext2_filsys fs,
 	} else
 		bitmap->description = 0;
 
-	size = (size_t) (((bitmap->real_end - bitmap->start) / 8) + 1);
+	size = (((size_t)bitmap->real_end - bitmap->start) / 8) + 1;
 	/* Round up to allow for the BT x86 instruction */
 	size = (size + 7) & ~3;
 	retval = ext2fs_get_mem(size, &bitmap->bitmap);
@@ -303,7 +303,7 @@ void ext2fs_clear_generic_bitmap(ext2fs_generic_bitmap bitmap)
 	}
 
 	memset(bitmap32->bitmap, 0,
-	       (size_t) (((bitmap32->real_end - bitmap32->start) / 8) + 1));
+	       (((size_t)bitmap32->real_end - bitmap32->start) / 8) + 1);
 }
 
 errcode_t ext2fs_fudge_generic_bitmap_end(ext2fs_inode_bitmap gen_bitmap,
diff --git a/src/ext2fs/inode.c b/src/ext2fs/inode.c
index c4377eeb..6e6c89f2 100644
--- a/src/ext2fs/inode.c
+++ b/src/ext2fs/inode.c
@@ -87,10 +87,11 @@ void ext2fs_free_inode_cache(struct ext2_inode_cache *icache)
 		return;
 	if (icache->buffer)
 		ext2fs_free_mem(&icache->buffer);
-	for (i = 0; i < icache->cache_size; i++)
-		ext2fs_free_mem(&icache->cache[i].inode);
-	if (icache->cache)
+	if (icache->cache) {
+		for (i = 0; i < icache->cache_size; i++)
+			ext2fs_free_mem(&icache->cache[i].inode);
 		ext2fs_free_mem(&icache->cache);
+	}
 	icache->buffer_blk = 0;
 	ext2fs_free_mem(&icache);
 }
diff --git a/src/ext2fs/nt_io.c b/src/ext2fs/nt_io.c
index a4231bef..36013af1 100644
--- a/src/ext2fs/nt_io.c
+++ b/src/ext2fs/nt_io.c
@@ -278,7 +278,7 @@ static __inline BOOLEAN _IsMounted(IN HANDLE Handle)
 {
 	IO_STATUS_BLOCK IoStatusBlock;
 	PF_INIT(NtFsControlFile, NtDll);
-	return (pfNtFsControlFile == NULL) ? STATUS_DLL_NOT_FOUND :
+	return (pfNtFsControlFile == NULL) ? FALSE :
 		(BOOLEAN)(pfNtFsControlFile(Handle, 0, 0, 0, &IoStatusBlock, FSCTL_IS_VOLUME_MOUNTED, 0, 0, 0, 0) == STATUS_SUCCESS);
 }
 
diff --git a/src/format.c b/src/format.c
index 8bf57bf8..eb492d17 100644
--- a/src/format.c
+++ b/src/format.c
@@ -1175,6 +1175,7 @@ static BOOL SetupWinPE(char drive_letter)
 	for (i=1; i<size-32; i++) {
 		for (j=0; j<ARRAYSIZE(patch_str_org); j++) {
 			if (safe_strnicmp(&buffer[i], patch_str_org[j], strlen(patch_str_org[j])-1) == 0) {
+				assert(index < 2);
 				uprintf("  0x%08X: '%s' -> '%s'\n", i, &buffer[i], patch_str_rep[index][j]);
 				strcpy(&buffer[i], patch_str_rep[index][j]);
 				i += (DWORD)max(strlen(patch_str_org[j]), strlen(patch_str_rep[index][j]));	// in case org is a substring of rep
@@ -2093,6 +2094,7 @@ DWORD WINAPI FormatThread(void* param)
 	if ((hLogicalVolume != NULL) && (hLogicalVolume != INVALID_HANDLE_VALUE)) {
 		PrintInfoDebug(0, MSG_227);
 		if (!CloseHandle(hLogicalVolume)) {
+			hLogicalVolume = INVALID_HANDLE_VALUE;
 			uprintf("Could not close volume: %s", WindowsErrorString());
 			FormatStatus = ERROR_SEVERITY_ERROR|FAC(FACILITY_STORAGE)|ERROR_ACCESS_DENIED;
 			goto out;
diff --git a/src/format_ext.c b/src/format_ext.c
index 6fbc5100..e60f926b 100644
--- a/src/format_ext.c
+++ b/src/format_ext.c
@@ -1,7 +1,7 @@
 /*
  * Rufus: The Reliable USB Formatting Utility
  * extfs formatting
- * Copyright © 2019-2020 Pete Batard <pete@akeo.ie>
+ * Copyright © 2019-2021 Pete Batard <pete@akeo.ie>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -212,6 +212,7 @@ const char* GetExtFsLabel(DWORD DriveIndex, uint64_t PartitionOffset)
 	r = ext2fs_open(volume_name, EXT2_FLAG_SKIP_MMP, 0, 0, manager, &ext2fs);
 	free(volume_name);
 	if (r == 0) {
+		assert(ext2fs != NULL);
 		strncpy(label, ext2fs->super->s_volume_name, EXT2_LABEL_LEN);
 		label[EXT2_LABEL_LEN] = 0;
 	}
diff --git a/src/format_fat32.c b/src/format_fat32.c
index 1fd1d32d..087c8b2d 100644
--- a/src/format_fat32.c
+++ b/src/format_fat32.c
@@ -2,7 +2,7 @@
  * Rufus: The Reliable USB Formatting Utility
  * Large FAT32 formatting
  * Copyright © 2007-2009 Tom Thornhill/Ridgecrop
- * Copyright © 2011-2020 Pete Batard <pete@akeo.ie>
+ * Copyright © 2011-2021 Pete Batard <pete@akeo.ie>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -414,7 +414,7 @@ BOOL FormatLargeFAT32(DWORD DriveIndex, uint64_t PartitionOffset, DWORD ClusterS
 	}
 
 	for (i = 0; i < (SystemAreaSize + BurstSize - 1); i += BurstSize) {
-		UpdateProgressWithInfo(OP_FORMAT, MSG_217, (uint64_t)i, (uint64_t)(SystemAreaSize + BurstSize));
+		UpdateProgressWithInfo(OP_FORMAT, MSG_217, (uint64_t)i, (uint64_t)SystemAreaSize + BurstSize);
 		CHECK_FOR_USER_CANCEL;
 		if (write_sectors(hLogicalVolume, BytesPerSect, i, BurstSize, pZeroSect) != (BytesPerSect * BurstSize)) {
 			die("Error clearing reserved sectors", ERROR_WRITE_FAULT);
diff --git a/src/icon.c b/src/icon.c
index b717cd02..2dd5882c 100644
--- a/src/icon.c
+++ b/src/icon.c
@@ -1,7 +1,7 @@
 /*
  * Rufus: The Reliable USB Formatting Utility
  * Extract icon from executable and set autorun.inf
- * Copyright © 2012-2019 Pete Batard <pete@akeo.ie>
+ * Copyright © 2012-2021 Pete Batard <pete@akeo.ie>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -26,6 +26,7 @@
 #include <windows.h>
 #include <stdio.h>
 #include <string.h>
+#include <assert.h>
 
 #include "rufus.h"
 #include "missing.h"
@@ -185,7 +186,8 @@ BOOL SetAutorun(const char* path)
 	uprintf("Created: %s", filename);
 
 	// .inf -> .ico
-	filename[strlen(filename)-1] = 'o';
-	filename[strlen(filename)-2] = 'c';
+	assert(strlen(filename) >= 2);
+	filename[strlen(filename) - 1] = 'o';
+	filename[strlen(filename) - 2] = 'c';
 	return ExtractAppIcon(filename, FALSE);
 }
diff --git a/src/iso.c b/src/iso.c
index cf55c00f..63d152a0 100644
--- a/src/iso.c
+++ b/src/iso.c
@@ -180,7 +180,7 @@ static BOOL check_iso_props(const char* psz_dirname, int64_t file_length, const
 
 	// Check for archiso loader/entries/*.conf files
 	if (safe_stricmp(psz_dirname, "/loader/entries") == 0) {
-		len = strlen(psz_basename);
+		len = safe_strlen(psz_basename);
 		props->is_conf = ((len > 4) && (stricmp(&psz_basename[len - 5], ".conf") == 0));
 	}
 
@@ -863,7 +863,7 @@ BOOL ExtractISO(const char* src_iso, const char* dest_dir, BOOL scan)
 	size_t i, j, size, sl_index = 0;
 	uint16_t sl_version;
 	FILE* fd;
-	int r = 1;
+	int k, r = 1;
 	iso9660_t* p_iso = NULL;
 	iso9660_pvd_t pvd;
 	udf_t* p_udf = NULL;
@@ -969,8 +969,8 @@ out:
 		if ((iso9660_ifs_read_pvd(p_iso, &pvd)) && (_stat64U(src_iso, &stat) == 0))
 			img_report.mismatch_size = (int64_t)(iso9660_get_pvd_space_size(&pvd)) * ISO_BLOCKSIZE - stat.st_size;
 		// Remove trailing spaces from the label
-		for (j=safe_strlen(img_report.label)-1; ((j>0)&&(isspaceU(img_report.label[j]))); j--)
-			img_report.label[j] = 0;
+		for (k=(int)safe_strlen(img_report.label)-1; ((k>0)&&(isspaceU(img_report.label[k]))); k--)
+			img_report.label[k] = 0;
 		// We use the fact that UDF_BLOCKSIZE and ISO_BLOCKSIZE are the same here
 		img_report.projected_size = total_blocks * ISO_BLOCKSIZE;
 		// We will link the existing isolinux.cfg from a syslinux.cfg we create
diff --git a/src/libcdio/iso9660/iso9660_fs.c b/src/libcdio/iso9660/iso9660_fs.c
index c6b8ae48..079b3b03 100644
--- a/src/libcdio/iso9660/iso9660_fs.c
+++ b/src/libcdio/iso9660/iso9660_fs.c
@@ -937,7 +937,7 @@ _iso9660_dir_to_statbuf (iso9660_dir_t *p_iso9660_dir,
     if (su_length % 2)
       su_length--;
 
-    if (su_length < 0 || su_length < sizeof (iso9660_xa_t))
+    if (su_length < sizeof (iso9660_xa_t))
       return p_stat;
 
     if (nope == b_xa) {
diff --git a/src/missing.h b/src/missing.h
index 729ec66c..0689b827 100644
--- a/src/missing.h
+++ b/src/missing.h
@@ -89,12 +89,12 @@ static __inline uint8_t popcnt8(uint8_t val)
 
 static __inline uint8_t popcnt64(register uint64_t u)
 {
-	u = (u & 0x5555555555555555) + ((u >> 1) & 0x5555555555555555);
-	u = (u & 0x3333333333333333) + ((u >> 2) & 0x3333333333333333);
-	u = (u & 0x0f0f0f0f0f0f0f0f) + ((u >> 4) & 0x0f0f0f0f0f0f0f0f);
-	u = (u & 0x00ff00ff00ff00ff) + ((u >> 8) & 0x00ff00ff00ff00ff);
-	u = (u & 0x0000ffff0000ffff) + ((u >> 16) & 0x0000ffff0000ffff);
-	u = (u & 0x00000000ffffffff) + ((u >> 32) & 0x00000000ffffffff);
+	u = (u & 0x5555555555555555ULL) + ((u >> 1) & 0x5555555555555555ULL);
+	u = (u & 0x3333333333333333ULL) + ((u >> 2) & 0x3333333333333333ULL);
+	u = (u & 0x0f0f0f0f0f0f0f0fULL) + ((u >> 4) & 0x0f0f0f0f0f0f0f0fULL);
+	u = (u & 0x00ff00ff00ff00ffULL) + ((u >> 8) & 0x00ff00ff00ff00ffULL);
+	u = (u & 0x0000ffff0000ffffULL) + ((u >> 16) & 0x0000ffff0000ffffULL);
+	u = (u & 0x00000000ffffffffULL) + ((u >> 32) & 0x00000000ffffffffULL);
 	return (uint8_t)u;
 }
 
diff --git a/src/msapi_utf8.h b/src/msapi_utf8.h
index 521f9d80..779a7d49 100644
--- a/src/msapi_utf8.h
+++ b/src/msapi_utf8.h
@@ -821,7 +821,7 @@ static __inline int SHDeleteDirectoryExU(HWND hwnd, const char* pszPath, FILEOP_
 	int ret;
 	// String needs to be double NULL terminated, so we just use the length of the UTF-8 string
 	// which is always expected to be larger than our UTF-16 one, and add 2 chars for good measure.
-	size_t wpszPath_len = strlen(pszPath) + 2;
+	size_t wpszPath_len = (pszPath == NULL) ? 0 : strlen(pszPath) + 2;
 	// coverity[returned_null]
 	walloc(pszPath, wpszPath_len);
 	SHFILEOPSTRUCTW shfo = { hwnd, FO_DELETE, wpszPath, NULL, fFlags, FALSE, NULL, NULL };
diff --git a/src/parser.c b/src/parser.c
index 878ca324..0a326624 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -1,7 +1,7 @@
 /*
  * Rufus: The Reliable USB Formatting Utility
  * Elementary Unicode compliant find/replace parser
- * Copyright © 2012-2020 Pete Batard <pete@akeo.ie>
+ * Copyright © 2012-2021 Pete Batard <pete@akeo.ie>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -796,13 +796,20 @@ char* set_token_data_file(const char* token, const char* data, const char* filen
 	}
 
 out:
-	if (fd_in != NULL) fclose(fd_in);
-	if (fd_out != NULL) fclose(fd_out);
+	if (fd_in != NULL) {
+		fclose(fd_in);
+		fd_in = NULL;
+	}
+	if (fd_out != NULL) {
+		fclose(fd_out);
+		fd_out = NULL;
+	}
 
 	// If an insertion occurred, delete existing file and use the new one
 	if (ret != NULL) {
 		// We're in Windows text mode => Remove CRs if requested
-		fd_in = _wfopen(wtmpname, L"rb");
+		if (wtmpname != NULL)
+			fd_in = _wfopen(wtmpname, L"rb");
 		fd_out = _wfopen(wfilename, L"wb");
 		// Don't check fds
 		if ((fd_in != NULL) && (fd_out != NULL)) {
@@ -1052,7 +1059,7 @@ out:
 	if (fd_out != NULL) fclose(fd_out);
 
 	// If an insertion occurred, delete existing file and use the new one
-	if (ret != NULL) {
+	if (ret != NULL && wtmpname != NULL && wfilename != NULL) {
 		// We're in Windows text mode => Remove CRs if requested
 		fd_in = _wfopen(wtmpname, L"rb");
 		fd_out = _wfopen(wfilename, L"wb");
@@ -1229,7 +1236,7 @@ out:
 	if (fd_out != NULL) fclose(fd_out);
 
 	// If a replacement occurred, delete existing file and use the new one
-	if (ret != NULL) {
+	if (ret != NULL && wtmpname != NULL && wfilename != NULL) {
 		// We're in Windows text mode => Remove CRs if requested
 		fd_in = _wfopen(wtmpname, L"rb");
 		fd_out = _wfopen(wfilename, L"wb");
diff --git a/src/process.c b/src/process.c
index 83ce771e..b5e91abc 100644
--- a/src/process.c
+++ b/src/process.c
@@ -4,7 +4,7 @@
  *
  * Modified from Process Hacker:
  *   https://github.com/processhacker2/processhacker2/
- * Copyright © 2017-2020 Pete Batard <pete@akeo.ie>
+ * Copyright © 2017-2021 Pete Batard <pete@akeo.ie>
  * Copyright © 2017 dmex
  * Copyright © 2009-2016 wj32
  *
@@ -506,6 +506,9 @@ static DWORD WINAPI SearchProcessThread(LPVOID param)
 		if (i >= handles->NumberOfHandles)
 			break;
 
+		if (handleInfo == NULL)
+			continue;
+
 		// Don't bother with processes we can't access
 		if (handleInfo->UniqueProcessId == last_access_denied_pid)
 			continue;
@@ -609,7 +612,7 @@ static DWORD WINAPI SearchProcessThread(LPVOID param)
 
 		// The above may not work on Windows 7, so try QueryFullProcessImageName (Vista or later)
 		if (!bGotCmdLine) {
-			bGotCmdLine = QueryFullProcessImageNameW(processHandle, 0, wexe_path, &size);
+			bGotCmdLine = (QueryFullProcessImageNameW(processHandle, 0, wexe_path, &size) != FALSE);
 			if (bGotCmdLine)
 				wchar_to_utf8_no_alloc(wexe_path, cmdline, sizeof(cmdline));
 		}
diff --git a/src/rufus.c b/src/rufus.c
index e3aac859..2b02cc05 100755
--- a/src/rufus.c
+++ b/src/rufus.c
@@ -751,9 +751,6 @@ static void EnableMBRBootOptions(BOOL enable, BOOL remove_checkboxes)
 			actual_enable_mbr = FALSE;
 			mbr_selected_by_user = FALSE;
 		}
-		if (boot_type == BT_NON_BOOTABLE) {
-			actual_enable_fix = FALSE;
-		}
 	}
 
 	if (remove_checkboxes) {
@@ -1135,6 +1132,7 @@ static void DisplayISOProps(void)
 	PRINT_ISO_PROP(HAS_WINPE(img_report), "  Uses: WinPE %s", (img_report.uses_minint) ? "(with /minint)" : "");
 	if (HAS_WININST(img_report)) {
 		inst_str[4] = '0' + img_report.wininst_index;
+		assert(strlen(img_report.wininst_path[0]) >= 3);
 		uprintf("  Uses: Install.%s%s (version %d.%d.%d%s)", &img_report.wininst_path[0][strlen(img_report.wininst_path[0]) - 3],
 			(img_report.wininst_index > 1) ? inst_str : "", (img_report.wininst_version >> 24) & 0xff,
 			(img_report.wininst_version >> 16) & 0xff, (img_report.wininst_version >> 8) & 0xff,
@@ -2218,6 +2216,7 @@ static INT_PTR CALLBACK MainCallback(HWND hDlg, UINT message, WPARAM wParam, LPA
 	static SHChangeNotifyEntry NotifyEntry;
 	static DWORD_PTR thread_affinity[CHECKSUM_MAX + 1];
 	static HFONT hyperlink_font = NULL;
+	static wchar_t wtooltip[128];
 	LONG lPos;
 	BOOL set_selected_fs;
 	DRAWITEMSTRUCT* pDI;
@@ -2234,7 +2233,6 @@ static INT_PTR CALLBACK MainCallback(HWND hDlg, UINT message, WPARAM wParam, LPA
 	char tmp[MAX_PATH], *log_buffer = NULL;
 	wchar_t* wbuffer = NULL;
 	loc_cmd* lcmd = NULL;
-	wchar_t wtooltip[128];
 
 	switch (message) {
 
diff --git a/src/rufus.h b/src/rufus.h
index 50dc0d48..d50c7615 100644
--- a/src/rufus.h
+++ b/src/rufus.h
@@ -132,7 +132,7 @@
 #ifndef STRINGIFY
 #define STRINGIFY(x)                #x
 #endif
-#define PERCENTAGE(percent, value)  ((1ULL * percent * value) / 100ULL)
+#define PERCENTAGE(percent, value)  ((1ULL * (percent) * (value)) / 100ULL)
 #define IsChecked(CheckBox_ID)      (IsDlgButtonChecked(hMainDialog, CheckBox_ID) == BST_CHECKED)
 #define MB_IS_RTL                   (right_to_left_mode?MB_RTLREADING|MB_RIGHT:0)
 #define CHECK_FOR_USER_CANCEL       if (IS_ERROR(FormatStatus) && (SCODE_CODE(FormatStatus) == ERROR_CANCELLED)) goto out
@@ -149,7 +149,7 @@
 	((char*)(dst))[safe_min(count, dst_max)-1] = 0;} while(0)
 #define safe_strcpy(dst, dst_max, src) safe_strcp(dst, dst_max, src, safe_strlen(src)+1)
 #define static_strcpy(dst, src) safe_strcpy(dst, sizeof(dst), src)
-#define safe_strncat(dst, dst_max, src, count) strncat(dst, src, safe_min(count, dst_max - safe_strlen(dst) - 1))
+#define safe_strncat(dst, dst_max, src, count) strncat(dst, src, safe_min(count, (dst_max) - safe_strlen(dst) - 1))
 #define safe_strcat(dst, dst_max, src) safe_strncat(dst, dst_max, src, safe_strlen(src)+1)
 #define static_strcat(dst, src) safe_strcat(dst, sizeof(dst), src)
 #define safe_strcmp(str1, str2) strcmp(((str1==NULL)?"<NULL>":str1), ((str2==NULL)?"<NULL>":str2))
@@ -178,7 +178,7 @@ extern void _uprintfs(const char *str);
 #define vvuprintf(...) do { if (verbose > 1) _uprintf(__VA_ARGS__); } while(0)
 #define suprintf(...) do { if (!bSilent) _uprintf(__VA_ARGS__); } while(0)
 #define uuprintf(...) do { if (usb_debug) _uprintf(__VA_ARGS__); } while(0)
-#define ubprintf(...) do { safe_sprintf(&ubuffer[ubuffer_pos], UBUFFER_SIZE - ubuffer_pos - 2, __VA_ARGS__); \
+#define ubprintf(...) do { safe_sprintf(&ubuffer[ubuffer_pos], UBUFFER_SIZE - ubuffer_pos - 4, __VA_ARGS__); \
 	ubuffer_pos = strlen(ubuffer); ubuffer[ubuffer_pos++] = '\r'; ubuffer[ubuffer_pos++] = '\n'; \
 	ubuffer[ubuffer_pos] = 0; } while(0)
 #define ubflush() do { if (ubuffer_pos) uprintf("%s", ubuffer); ubuffer_pos = 0; } while(0)
@@ -389,7 +389,7 @@ typedef struct {
 	BOOLEAN has_kolibrios;
 	BOOLEAN uses_casper;
 	BOOLEAN uses_minint;
-	BOOLEAN compression_type;
+	uint8_t compression_type;
 	winver_t win_version;	// Windows ISO version
 	uint16_t sl_version;	// Syslinux/Isolinux version
 	char sl_version_str[12];
diff --git a/src/rufus.rc b/src/rufus.rc
index bb970462..f26a363e 100644
--- a/src/rufus.rc
+++ b/src/rufus.rc
@@ -33,7 +33,7 @@ LANGUAGE LANG_NEUTRAL, SUBLANG_NEUTRAL
 IDD_DIALOG DIALOGEX 12, 12, 232, 326
 STYLE DS_SETFONT | DS_MODALFRAME | DS_CENTER | WS_MINIMIZEBOX | WS_POPUP | WS_CAPTION | WS_SYSMENU
 EXSTYLE WS_EX_ACCEPTFILES
-CAPTION "Rufus 3.18.1854"
+CAPTION "Rufus 3.18.1855"
 FONT 9, "Segoe UI Symbol", 400, 0, 0x0
 BEGIN
     LTEXT           "Drive Properties",IDS_DRIVE_PROPERTIES_TXT,8,6,53,12,NOT WS_GROUP
@@ -395,8 +395,8 @@ END
 //
 
 VS_VERSION_INFO VERSIONINFO
- FILEVERSION 3,18,1854,0
- PRODUCTVERSION 3,18,1854,0
+ FILEVERSION 3,18,1855,0
+ PRODUCTVERSION 3,18,1855,0
  FILEFLAGSMASK 0x3fL
 #ifdef _DEBUG
  FILEFLAGS 0x1L
@@ -414,13 +414,13 @@ BEGIN
             VALUE "Comments", "https://rufus.ie"
             VALUE "CompanyName", "Akeo Consulting"
             VALUE "FileDescription", "Rufus"
-            VALUE "FileVersion", "3.18.1854"
+            VALUE "FileVersion", "3.18.1855"
             VALUE "InternalName", "Rufus"
             VALUE "LegalCopyright", "© 2011-2021 Pete Batard (GPL v3)"
             VALUE "LegalTrademarks", "https://www.gnu.org/licenses/gpl-3.0.html"
             VALUE "OriginalFilename", "rufus-3.18.exe"
             VALUE "ProductName", "Rufus"
-            VALUE "ProductVersion", "3.18.1854"
+            VALUE "ProductVersion", "3.18.1855"
         END
     END
     BLOCK "VarFileInfo"
diff --git a/src/stdio.c b/src/stdio.c
index 50b80c18..a9df73a4 100644
--- a/src/stdio.c
+++ b/src/stdio.c
@@ -662,7 +662,7 @@ const char *WindowsErrorString(void)
 
 	size = FormatMessageU(FORMAT_MESSAGE_FROM_SYSTEM|FORMAT_MESSAGE_IGNORE_INSERTS, NULL,
 		HRESULT_CODE(error_code), MAKELANGID(LANG_ENGLISH, SUBLANG_ENGLISH_US),
-		&err_string[presize], sizeof(err_string)-(DWORD)strlen(err_string), NULL);
+		&err_string[presize], (DWORD)(sizeof(err_string)-strlen(err_string)), NULL);
 	if (size == 0) {
 		format_error = GetLastError();
 		if ((format_error) && (format_error != ERROR_MR_MID_NOT_FOUND) && (format_error != ERROR_MUI_FILE_NOT_LOADED))
diff --git a/src/stdlg.c b/src/stdlg.c
index 088176d9..33046aec 100644
--- a/src/stdlg.c
+++ b/src/stdlg.c
@@ -155,9 +155,12 @@ void BrowseForFolder(void) {
 	dialog_showing++;
 	hr = CoCreateInstance(&CLSID_FileOpenDialog, NULL, CLSCTX_INPROC,
 		&IID_IFileOpenDialog, (LPVOID)&pfod);
-	if (FAILED(hr)) {
+	if (FAILED(hr) || pfod == NULL) {
 		uprintf("CoCreateInstance for FileOpenDialog failed: error %X\n", hr);
-		pfod = NULL;	// Just in case
+		if (pfod != NULL) {
+			IFileOpenDialog_Release(pfod);
+			pfod = NULL;	// Just in case
+		}
 		goto fallback;
 	}
 	hr = IFileOpenDialog_SetOptions(pfod, FOS_PICKFOLDERS);
@@ -180,7 +183,7 @@ void BrowseForFolder(void) {
 	}
 
 	hr = SHCreateItemFromParsingName(wpath, NULL, &IID_IShellItem, (LPVOID)&si_path);
-	if (SUCCEEDED(hr)) {
+	if (SUCCEEDED(hr) && pfod != NULL) {
 		if (wpath != NULL) {
 			IFileOpenDialog_SetFolder(pfod, si_path);
 		}
@@ -191,7 +194,7 @@ void BrowseForFolder(void) {
 	safe_free(wpath);
 
 	hr = IFileOpenDialog_Show(pfod, hMainDialog);
-	if (SUCCEEDED(hr)) {
+	if (SUCCEEDED(hr) && pfod != NULL) {
 		hr = IFileOpenDialog_GetResult(pfod, &psi);
 		if (SUCCEEDED(hr)) {
 			IShellItem_GetDisplayName(psi, SIGDN_FILESYSPATH, &wpath);
@@ -277,7 +280,10 @@ char* FileDialog(BOOL save, char* path, const ext_t* ext, DWORD options)
 		if (FAILED(hr)) {
 			SetLastError(hr);
 			uprintf("CoCreateInstance for FileOpenDialog failed: %s\n", WindowsErrorString());
-			pfd = NULL;	// Just in case
+			if (pfd != NULL) {
+				IFileDialog_Release(pfd);
+				pfd = NULL;	// Just in case
+			}
 			goto fallback;
 		}
 
@@ -789,8 +795,8 @@ INT_PTR CALLBACK NotificationCallback(HWND hDlg, UINT message, WPARAM wParam, LP
 			EndDialog(hDlg, LOWORD(wParam));
 			return (INT_PTR)TRUE;
 		case IDC_MORE_INFO:
-			assert(notification_more_info->callback != NULL);
 			if (notification_more_info != NULL) {
+				assert(notification_more_info->callback != NULL);
 				if (notification_more_info->id == MORE_INFO_URL) {
 					ShellExecuteA(hDlg, "open", notification_more_info->url, NULL, NULL, SW_SHOWNORMAL);
 				} else {
@@ -1613,7 +1619,7 @@ BOOL SetUpdateCheck(void)
 		}
 		// If the user hasn't set the interval in the dialog, set to default
 		if ( (ReadSetting32(SETTING_UPDATE_INTERVAL) == 0) ||
-			 ((ReadSetting32(SETTING_UPDATE_INTERVAL) == -1) && enable_updates) )
+			 (ReadSetting32(SETTING_UPDATE_INTERVAL) == -1) )
 			WriteSetting32(SETTING_UPDATE_INTERVAL, 86400);
 	}
 	SetFidoCheck();
@@ -2005,7 +2011,7 @@ static BOOL CALLBACK AlertPromptCallback(HWND hWnd, LPARAM lParam)
 
 	if (GetWindowTextU(hWnd, str, sizeof(str)) == 0)
 		return TRUE;
-	if (safe_strcmp(str, button_str) == 0)
+	if (strcmp(str, button_str) == 0)
 		*found = TRUE;
 	return TRUE;
 }
diff --git a/src/syslinux.c b/src/syslinux.c
index ba6583cb..6c154590 100644
--- a/src/syslinux.c
+++ b/src/syslinux.c
@@ -194,7 +194,7 @@ BOOL InstallSyslinux(DWORD drive_index, char drive_letter, int file_system)
 	}
 
 	/* Create ldlinux.sys file */
-	static_sprintf(path, "%C:\\%s.%s", drive_letter, ldlinux, ldlinux_ext[0]);
+	static_sprintf(path, "%c:\\%s.%s", drive_letter, ldlinux, ldlinux_ext[0]);
 	f_handle = CreateFileA(path, GENERIC_READ | GENERIC_WRITE,
 			  FILE_SHARE_READ | FILE_SHARE_WRITE,
 			  NULL, CREATE_ALWAYS,
@@ -236,7 +236,7 @@ BOOL InstallSyslinux(DWORD drive_index, char drive_letter, int file_system)
 
 	switch (file_system) {
 	case FS_NTFS:
-		static_sprintf(tmp, "%C:\\", drive_letter);
+		static_sprintf(tmp, "%c:\\", drive_letter);
 		vol_info.Handle = d_handle;
 		err = NtfsSectGetVolumeInfo(tmp, &vol_info);
 		if (err != ERROR_SUCCESS) {
@@ -333,7 +333,7 @@ BOOL InstallSyslinux(DWORD drive_index, char drive_letter, int file_system)
 		IGNORE_RETVAL(_chdirU(app_data_dir));
 		static_sprintf(path, "%s\\%s-%s", FILES_DIR, syslinux, embedded_sl_version_str[1]);
 		IGNORE_RETVAL(_chdir(path));
-		static_sprintf(path, "%C:\\%s.%s", drive_letter, ldlinux, ldlinux_ext[2]);
+		static_sprintf(path, "%c:\\%s.%s", drive_letter, ldlinux, ldlinux_ext[2]);
 		fd = fopen(&path[3], "rb");
 		if (fd == NULL) {
 			uprintf("Caution: No '%s' was provided. The target will be missing a required Syslinux file!", &path[3]);
@@ -354,7 +354,7 @@ BOOL InstallSyslinux(DWORD drive_index, char drive_letter, int file_system)
 			goto out;
 		}
 		/* Create mboot.c32 file */
-		static_sprintf(path, "%C:\\%s", drive_letter, mboot_c32);
+		static_sprintf(path, "%c:\\%s", drive_letter, mboot_c32);
 		f_handle = CreateFileA(path, GENERIC_READ | GENERIC_WRITE,
 				  FILE_SHARE_READ | FILE_SHARE_WRITE,
 				  NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
@@ -368,7 +368,7 @@ BOOL InstallSyslinux(DWORD drive_index, char drive_letter, int file_system)
 			goto out;
 		}
 		safe_closehandle(f_handle);
-		static_sprintf(path, "%C:\\syslinux.cfg", drive_letter);
+		static_sprintf(path, "%c:\\syslinux.cfg", drive_letter);
 		fd = fopen(path, "w");
 		if (fd == NULL) {
 			uprintf("Could not create ReactOS 'syslinux.cfg'");
diff --git a/src/ui.c b/src/ui.c
index 8db33a80..806d48cd 100644
--- a/src/ui.c
+++ b/src/ui.c
@@ -575,8 +575,9 @@ void SetSectionHeaders(HWND hDlg)
 		SendDlgItemMessageA(hDlg, section_control_ids[i], WM_SETFONT, (WPARAM)hf, TRUE);
 		hCtrl = GetDlgItem(hDlg, section_control_ids[i]);
 		memset(wtmp, 0, sizeof(wtmp));
-		GetWindowTextW(hCtrl, wtmp, ARRAYSIZE(wtmp) - 3);
+		GetWindowTextW(hCtrl, wtmp, ARRAYSIZE(wtmp) - 4);
 		wlen = wcslen(wtmp);
+		assert(wlen < ARRAYSIZE(wtmp - 2));
 		wtmp[wlen++] = L' ';
 		wtmp[wlen++] = L' ';
 		SetWindowTextW(hCtrl, wtmp);
@@ -788,8 +789,7 @@ void ToggleImageOptions(void)
 	if (image_option_txt[0] == 0)
 		GetWindowTextU(GetDlgItem(hMainDialog, IDS_IMAGE_OPTION_TXT), image_option_txt, sizeof(image_option_txt));
 
-	if ( ((has_wintogo) && !(image_options & IMOP_WINTOGO)) ||
-		 ((!has_wintogo) && (image_options & IMOP_WINTOGO)) ) {
+	if ((has_wintogo) != (image_options & IMOP_WINTOGO)) {
 		image_options ^= IMOP_WINTOGO;
 		if (image_options & IMOP_WINTOGO) {
 			// Set the Windows To Go selection in the dropdown
@@ -797,8 +797,7 @@ void ToggleImageOptions(void)
 		}
 	}
 
-	if (((has_persistence) && !(image_options & IMOP_PERSISTENCE)) ||
-		((!has_persistence) && (image_options & IMOP_PERSISTENCE))) {
+	if ((has_persistence) != (image_options & IMOP_PERSISTENCE)) {
 		image_options ^= IMOP_PERSISTENCE;
 		if (image_options & IMOP_PERSISTENCE) {
 			SetWindowTextU(GetDlgItem(hMainDialog, IDS_IMAGE_OPTION_TXT), lmprintf(MSG_123));
@@ -1069,7 +1068,7 @@ void CreateAdditionalControls(HWND hDlg)
 	hAdvancedDeviceToolbar = CreateWindowEx(0, TOOLBARCLASSNAME, NULL, TOOLBAR_STYLE,
 		0, 0, 0, 0, hMainDialog, (HMENU)IDC_ADVANCED_DEVICE_TOOLBAR, hMainInstance, NULL);
 	SendMessage(hAdvancedDeviceToolbar, CCM_SETVERSION, (WPARAM)6, 0);
-	memset(tbToolbarButtons, 0, sizeof(TBBUTTON));
+	memset(tbToolbarButtons, 0, sizeof(tbToolbarButtons));
 	tbToolbarButtons[0].idCommand = IDC_ADVANCED_DRIVE_PROPERTIES;
 	tbToolbarButtons[0].fsStyle = BTNS_SHOWTEXT | BTNS_AUTOSIZE;
 	tbToolbarButtons[0].fsState = TBSTATE_ENABLED;
@@ -1091,7 +1090,7 @@ void CreateAdditionalControls(HWND hDlg)
 	hAdvancedFormatToolbar = CreateWindowEx(0, TOOLBARCLASSNAME, NULL, TOOLBAR_STYLE,
 		0, 0, 0, 0, hMainDialog, (HMENU)IDC_ADVANCED_FORMAT_TOOLBAR, hMainInstance, NULL);
 	SendMessage(hAdvancedFormatToolbar, CCM_SETVERSION, (WPARAM)6, 0);
-	memset(tbToolbarButtons, 0, sizeof(TBBUTTON));
+	memset(tbToolbarButtons, 0, sizeof(tbToolbarButtons));
 	tbToolbarButtons[0].idCommand = IDC_ADVANCED_FORMAT_OPTIONS;
 	tbToolbarButtons[0].fsStyle = BTNS_SHOWTEXT | BTNS_AUTOSIZE;
 	tbToolbarButtons[0].fsState = TBSTATE_ENABLED;