Troubleshooting · Windows Security
SmartScreen Warning on the ScanTailor ZIP? Verify It, Then Run It Safely
“Windows protected your PC” — Microsoft Defender SmartScreen stopped the ScanTailor Advanced ZIP or program because it is “untrusted”. For unsigned open-source software this warning is expected. The safe response is not to ignore it blindly: verify the file’s SHA-256 first, then run it.
The Symptom
- A blue SmartScreen panel: “Windows protected your PC — Microsoft Defender SmartScreen prevented an unrecognized app from starting.”
- Your browser or Windows flags the downloaded ZIP as untrusted or rarely downloaded.
- The panel offers no obvious “Run” button — only “Don’t run”.
The Cause
Windows trusts programs partly by their digital signature. Commercial software is signed with a paid code-signing certificate; community-built open-source releases like ScanTailor Advanced are distributed unsigned, so SmartScreen has no publisher signature and little download history to judge them by — and warns you. The warning tells you the file is unsigned, not that it is infected. That distinction is exactly why verification matters: your job is to confirm the file you have is bit-for-bit the file the project published.
The Fix, Step by Step
1. Verify the SHA-256 before running anything
Open PowerShell in the folder where the ZIP sits and run:
Get-FileHash .\ScanTailor-Advanced-1.1.1×64.zip -Algorithm SHA256
For the official Windows v1.1.1 release, the result must be:
d03c9eebdf8c9196941d8a0a9a8ca52a6b6e2ed7415f362a313e7f0bd76283ab
The same hash is published on the download page next to the official GitHub link. If your value matches it exactly, you hold the genuine release file — the project published its SHA-256 digest with the release itself.
2. Only then: More info → Run anyway
Extract the verified ZIP and start the program. When SmartScreen appears, click “More info” — this reveals the “Run anyway” button. Click it, and the program starts. Windows generally remembers the decision for that file.
3. If the hash does not match — do not run it
Prevention
- Always download from the official project links (GitHub via the download page) — never from a random “free download” portal that repackages the ZIP; repackaged files are where real malware gets in.
- Make hash-checking a habit: it takes seconds and converts a vague “untrusted” warning into a definite yes or no.
- If the program starts but immediately closes after you ran it anyway, that is a different problem — work the won’t-open checklist.
More Windows fixes: the troubleshooting archive.
FAQ
Does a SmartScreen warning mean ScanTailor Advanced contains a virus?
No. It means the build is unsigned and not yet widely downloaded, so SmartScreen cannot vouch for it. The SHA-256 check is how you verify the file independently: if it matches the project’s published digest, it is the untouched release.
Why does Windows hide the “Run anyway” button?
By design: SmartScreen wants casual users to stop. Clicking “More info” expands the panel and reveals “Run anyway”. Only use it after your hash check passes.
My antivirus flagged the file too. What should I do?
Same rule: verify the SHA-256 first. A matching hash plus a generic “unsigned/unrecognized” style detection is the expected open-source situation. A matching hash is also your reason to restore the file from quarantine; a mismatching hash means delete it and re-download from the official link.