Microsoft Safety Scanner review

Microsoft Safety Scanner is the free fallback for PCs that other tools no longer support. Microsoft describes it as a scan tool designed to find and remove malware from Windows computers and to try to reverse changes made by identified threats. It runs on everything from Windows 11 back to Windows 7 and Windows Server 2008 R2, which is useful for an old family PC that newer scanners such as Emsisoft Emergency Kit will not run on. It is a portable executable, so there is nothing to install, and when you are done you simply delete msert.exe. The detailed log lands in the Windows debug folder. The trade-offs come from its design. Each download expires after 10 days, so you must fetch a fresh copy for current definitions, it scans only when you start it, and Microsoft states plainly that it does not replace a real-time anti-malware product.

Who it is for

Older Windows PCs, including Windows 7 and 8.1, that need a free one-off cleanup.

Price

Free download.

Microsoft Safety Scanner is a scan tool designed to find and remove malware from Windows computers.
Quoted from the vendor pricing page on November 10, 2026.

Key features

• Finds and removes malware and tries to reverse changes made by threats
• Portable executable, no installation
• Runs on Windows 11 back to Windows 7 and several Windows Server versions
• Detailed detection log at %SYSTEMROOT%\debug\msert.log
• 32-bit and 64-bit downloads

Strengths and weaknesses

• Strength: Free and made by Microsoft
• Strength: Supports older versions of Windows
• Strength: Nothing to uninstall: delete the file when done
• Weakness: Expires 10 days after download
• Weakness: Scans only when you start it
• Weakness: Microsoft says it does not replace your anti-malware product

Key facts

• Platforms: Windows 11 to Windows 7, Windows Server 2008 R2 to 2019
• Expiry: 10 days after download
• Install needed: No, portable executable
• Price: Free

Where it ranks

Microsoft Safety Scanner is No. 9 in our Best Malware Removal Tools verdict.