"This App Has Been Blocked for Your Protection" and "Windows Protected Your PC" — What to Do
You try to open an installer or app and Windows stops it with one of these:
“This app has been blocked for your protection” — or a blue box reading “Windows protected your PC — Microsoft Defender SmartScreen prevented an unrecognized app from starting.”
Why: These are two different blocks. The blue SmartScreen box means the app simply isn’t recognized yet (new or uncommon download) — you can run it anyway if you trust it. “This app has been blocked for your protection” is stricter: it usually means the app’s digital signature is expired, revoked, or from a publisher Windows distrusts. A third message, “blocked by your system administrator,” is a policy block. The right fix depends on which one you’re seeing — work through them below, but only proceed if you genuinely trust the source.
Fix 1: Blue SmartScreen box — “More info” then “Run anyway”
For the “Windows protected your PC” SmartScreen prompt:
- In the blue dialog, click More info.
- The app name and publisher appear; click Run anyway.
- If “Run anyway” doesn’t show, the file may be blocked at the file level — do Fix 3 first, then retry.
Only do this for software you downloaded from the official vendor. SmartScreen warns because the file is uncommon or unrecognized, not necessarily malicious — but bypassing it removes that safety check.
Fix 2: “Blocked for your protection” — run it from an admin prompt
This message often appears when the installer’s certificate is expired or revoked. The cleanest path is to get a fresh copy:
- Re-download from the official site. A new build is usually re-signed and runs normally. This is the safest fix and worth trying first.
If you must run the copy you have and you trust it completely:
- Right-click Start → Terminal (Admin) (or Command Prompt (Admin)).
- Type the full path to the file in quotes and press Enter, e.g.
"C:\Users\You\Downloads\setup.exe". Launching from an elevated prompt bypasses the standard-user block in many cases.
If the app is being blocked because its certificate was revoked, that can be a real warning — a revoked signature sometimes means the software was compromised. Prefer re-downloading from the vendor over forcing it to run.
Fix 3: Unblock a file downloaded from the internet
Files saved from the web get a “mark of the web” that can trigger blocks:
- In File Explorer, right-click the file → Properties.
- On the General tab, if you see “This file came from another computer and might be blocked,” tick Unblock.
- Click Apply → OK, then run the file again.
Fix 4: “Blocked by your system administrator” — managed devices and Smart App Control
- Work or school PC: this is an AppLocker / Smart App Control policy set by IT. There’s no end-user override — contact your administrator.
- Smart App Control (personal PC): Smart App Control only allows apps from known publishers, and there is no way to allow an individual app. Your choices are to ask the developer to sign the app, or turn Smart App Control off in Windows Security → App & browser control → Smart App Control settings. Note: once you turn Smart App Control off, it cannot be turned back on without resetting or reinstalling Windows — so only disable it deliberately.
FAQ
Is “This app has been blocked for your protection” a virus warning? Not exactly — it’s a signature/publisher-trust block, often an expired or revoked certificate. It can be a benign old installer, or a genuine red flag if the signature was revoked. Re-download from the official source to be sure.
Why is there no “Run anyway” on my block? “Run anyway” is the SmartScreen (blue box) experience. The “blocked for your protection” and “blocked by your administrator” messages don’t offer it; use Fix 2 or Fix 4 instead.
Should I just turn SmartScreen off? No. Leave SmartScreen on (App & browser control → Reputation-based protection) and bypass it case by case with “Run anyway” only for trusted apps.
Sources: Microsoft Support — Stay protected with Windows Security (SmartScreen & Smart App Control), Microsoft Support — Smart App Control frequently asked questions