What SmartScreen is, why it shows 'Windows protected your PC' for new downloads, and how to check a file before running it.
Microsoft Defender SmartScreen is a Windows security feature that checks downloaded apps and visited websites against Microsoft's reputation data. For files that few people have downloaded yet, it shows the blue 'Windows protected your PC' screen, even when the file is signed and clean.
SmartScreen judges files by reputation: how many people downloaded and ran them and whether problems were reported. A new program, or a new version, starts with little reputation, so warnings are common in its first weeks even with a valid code signature.
Download only from the publisher's official site. Check the digital signature (file Properties > Digital Signatures) and compare the SHA-256 hash with the one the publisher lists, for example with 'Get-FileHash <file> -Algorithm SHA256' in PowerShell.
If the publisher is unknown, the signature is missing or the hash differs, do not run the file.
SmartScreen is controlled in Windows Security > App & browser control > Reputation-based protection. Keeping it on is recommended.
Get-FileHash <path-to-file> -Algorithm SHA256Note: Rain Cleaner publishes its SHA-256 hashes and signature details on its Trust Center page.
Last updated: 2026-10-08
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