Why Windows SmartScreen warns about new apps
When Windows SmartScreen shows "Windows protected your PC" for a program, it usually means the app is new or unrecognized, not that it's malicious. SmartScreen flags software it hasn't seen enough of yet or that isn't signed with a recognized certificate. Here's what the warning actually checks and how to decide whether to continue.
What is Windows SmartScreen?
SmartScreen is a Microsoft safety feature built into Windows and Edge. When you run a downloaded program, it checks the file's reputation against Microsoft's records. Well-known apps from established publishers pass silently. Apps that are new, downloaded rarely, or not signed with a recognized code-signing certificate get the blue "Windows protected your PC" prompt instead.
Does the warning mean the app is a virus?
No — not on its own. The prompt means "unrecognized," not "confirmed malicious." A brand-new release from a small developer often triggers it simply because SmartScreen hasn't built up reputation data for that exact file yet, and because code-signing certificates are expensive and take time to establish trust. That said, "unrecognized" is a reason to check the source before you proceed, not to click through blindly.
How to check a download before you trust it
- Download only from the developer's official website or a reputable store, not a random mirror.
- Confirm the site uses HTTPS and the domain is the real one.
- If the developer publishes a SHA-256 checksum, compare it against your downloaded file.
- Check that later updates are signed and verified by the app itself.
- When in doubt, scan the file with your antivirus or an online multi-engine scanner.
How to continue past the prompt (when you trust the source)
If you've verified the source and want to proceed, click More info on the SmartScreen dialog, then Run anyway. If those options don't appear, the dialog may be from a different security tool rather than SmartScreen.
How this applies to PDM
Perfect Download Manager's installer isn't code-signed yet, so you may see this prompt on first install — click More info → Run anyway. A code-signing certificate is the permanent fix and is planned. In the meantime, PDM's own updates are ECDSA-signed and SHA-256 verified before they install, and we publish a SHA-256 checksum you can check. More detail is in our FAQ and the download section.