Windows 10 proactively scans for and blocks threats to a system. It does this by scanning files that are downloaded or apps that are run. If you have browser control enabled in Windows Defender, malicious files that you download will be scanned and blocked before you can even look at them.
Windows 10 will check a file when it’s downloaded and copied, but the SmartScreen will also check to see if it’s signed or not when you try to run it. This normally happens for files that are executables or that can be extracted.
Fix SmartScreen can’t be reached right now
SmartScreen will check files when you open/run them. Windows Defender will already have checked the file when it was downloaded but a second check will be done anyway.
In order to check the file, SmartScreen examines it for known markers of malicious files. These markers are always being updated to make sure new threats can be blocked. If you try to open/run an app, and see the “SmartScreen can’t be reached right now” error, here’s what you can do.
Check internet connection
SmartScreen works if you have an internet connection. Without an active internet connection, it can’t see the updated list of markers of a malicious file.
- Click the WiFi icon in the system tray.
- Look for your network in the panel.
- It should say ‘Connected, Secured’ or ‘Connected, Internet’ under it. If it doesn’t, you do not have internet access.
Check SmartScreen service status
SmartScreen is a service; it runs on the desktop but needs to communicate with an online server to work. If the server is down, you will see the “SmartScreen can’t be reached right now” error if your internet is working.
Unfortunately, there’s no go-to status page for the service. You’re going to have to check online forums, and various Microsoft Twitter accounts to check if the service is down.
SmartScreen can run into problems and toggling it Off and On can fix them.
- Open Windows Defender.
- Go to App and browser control.
- Click Reputation-based protection settings.
- Turn the “Check apps and files” switch off.
- Restart the system.
- Return to Windows Defender and turn the “Check apps and files” switch back on.
- Open the file and SmartScreen will scan it.
Turn off proxies and VPN
A proxy or a VPN should not interfere with the SmartScreen but there are always exceptions. If you’ve configured a proxy on Windows 10, or you’re using a VPN, turn them off and try to open the file.
Scan with VirusTotal
If the SmartScreen still isn’t working, you can try scanning the file with VirusTotal though it works only for exectuables.
- Visit VirustTotal.
- Click Choose File.
- Upload the file.
- Once the initial results are displayed, click the refresh arrow button on VirusTotal to run a fresh scan.
- If the file is safe, by-pass SmartScreen and open it.
SmartScreen is conservative when it comes to blocking files. It will block anything for seemingly harmless reasons.
While this is generally a good thing i.e., you want your antivirus to be overly cautious, it can sometimes be ignored. If you know the file is safe, by-pass SmartScreen.
- Double-click the file you want to run.
- On the “SmartScreen can’t be reached right now” screen, click Run Anyway.
- The file will open.
SmartScreen problems are rarely long-term. If the service has never worked since you installed Windows 10 or it stopped working after an update, you may need to roll the update back, wait for a patch update, or consider creating a new user.