SmartScreen can’t be reached right now: how to fix it

Applies to: Windows 11 and Windows 10, when opening downloaded apps and installers.

What the message means

When you open a file you downloaded from the internet, Microsoft Defender SmartScreen checks its reputation with Microsoft’s online service: is it a known, commonly downloaded app, or one reported as unsafe? If Windows can’t reach that service, it can’t give a verdict, so it shows a dialog saying SmartScreen is unavailable and asks you to check your internet connection. You then get a choice between Run anyway and Don’t run.

So the message isn’t a warning that the file is dangerous. It means the safety check didn’t happen. The fixes below restore the connection to SmartScreen so the check works again.

Fix 1: Check your internet connection

1. Open a website in your browser to confirm you’re online.
2. If you’re on Wi-Fi with a sign-in page (hotel, airport, café), complete the sign-in first.
3. Restart the PC and the router if pages load slowly or not at all.

If other Microsoft services also fail (for example Windows Update), the problem is the connection to Microsoft as a whole; see we couldn’t connect to the update service for network fixes that also apply here.

Fix 2: Turn off a proxy or VPN

A proxy or VPN that can’t reach Microsoft’s servers, or that intercepts secure connections, is a common cause.

1. Disconnect any VPN app and try opening the file again.
2. Open Settings > Network & internet > Proxy (Windows 10: Settings > Network & Internet > Proxy).
3. Under Manual proxy setup, turn off a proxy you don’t need. Leave Automatically detect settings on unless your network admin says otherwise.

You can also reset WinHTTP proxy settings, which some apps set without telling you. In Command Prompt as administrator, run:

netsh winhttp show proxy
netsh winhttp reset proxy

Only reset it on a home PC. On a work PC, the proxy is usually set on purpose.

Fix 3: Check the SmartScreen settings

1. Open Windows Security from the Start menu.
2. Go to App & browser control and select Reputation-based protection settings.
3. Make sure Check apps and files is on. While you’re there, check SmartScreen for Microsoft Edge and Potentially unwanted app blocking too.
4. If a setting is greyed out with This setting is managed by your administrator, it’s controlled by policy (see the FAQ).

If the switches were already on, turn Check apps and files off and on again, restart the PC, and try the file again.

Fix 4: Check the date, time and updates

SmartScreen uses secure connections, and those fail if the PC’s clock is far off.

1. Go to Settings > Time & language > Date & time.
2. Turn on Set time automatically and Set time zone automatically, then select Sync now.

Then run Settings > Windows Update and install pending updates, including security intelligence updates for Microsoft Defender.

Fix 5: Check firewalls and DNS filters

Third-party firewalls, parental-control tools, ad blockers that work at network level (such as Pi-hole or router-based filtering) and some “privacy” tweaking apps can block Microsoft’s SmartScreen servers. If you use one of these:

• Pause it briefly and try opening the file again.
• If that fixes it, look in the tool’s blocked-domain log for Microsoft SmartScreen entries and allow them.
• If a privacy tool changed Windows settings for you, undo its SmartScreen-related tweaks.

Fix 6: Repair Windows Security

If Windows Security itself won’t open or its pages are blank, repair the system files it depends on. In Command Prompt as administrator, run:

DISM /Online /Cleanup-Image /RestoreHealth
sfc /scannow

Restart when they finish. If SFC reports a problem it can’t fix, see Windows Resource Protection could not perform the requested operation.

Should you click Run anyway?

Only if you’re sure the file is safe. Without SmartScreen’s check, you’re relying on your own judgement, so:

• Check the source. Download apps only from the developer’s own website or the Microsoft Store, not from mirror sites or links in emails.
• Scan it first. Right-click the file and choose Scan with Microsoft Defender (on Windows 11 it may be under Show more options). For a full check of the PC, see how to scan for malware.
• Check the publisher. Right-click the file, open Properties and look at the Digital Signatures tab. A missing signature isn’t proof of malware, but a well-known app should be signed by its developer.

We don’t recommend turning SmartScreen off to make the message go away. It’s one of the main protections against malicious downloads, and the message usually disappears once the connection problem is fixed.

Related guides

• How to scan for malware on Windows
• We couldn’t connect to the update service
• Windows Resource Protection could not perform the requested operation

Official sources: for more detail, see Microsoft’s own documentation:

• Microsoft Learn: Microsoft Defender SmartScreen overview
• Microsoft Support: App & browser control in the Windows Security app

Frequently asked questions

Does this message mean the file is a virus?

No. It means SmartScreen couldn’t check the file. The file might be fine or harmful; the check simply didn’t happen.

Why does it only happen with some files?

SmartScreen mainly checks files that came from the internet. Apps you installed earlier, and files from local drives or network shares, usually don’t trigger a check.

The setting says it’s managed by my administrator. What now?

On a work or school PC, SmartScreen is controlled by your organization’s policies, and their network may block it on purpose. Contact your IT team. On a home PC, this message usually comes from a privacy or tweaking tool that changed policy settings.

Can I turn off SmartScreen to stop this message?

You can, but it removes an important layer of protection. Fix the connection instead, and if you must run one trusted file now, scan it and use Run anyway for that file only.