“SmartScreen can’t be reached right now”
This one is not about your file. Windows wanted to ask a Microsoft service what it knows about the download, could not get through, and told you so. Fixing the connection is the answer, and it is usually one of five dull things.
What to check, in order
- 01
Check the machine is actually online
SmartScreen asks a Microsoft service about the file, so with no working connection there is nothing to ask. A browser that loads pages is not proof on its own: a captive portal on hotel or office wifi answers web requests and blocks everything else.
- 02
Check the clock
The lookup happens over TLS, and TLS fails when the system date is wrong by enough. A machine whose battery died and came back in 2019 produces exactly this error, and fixing the time fixes it.
- 03
Turn off a VPN or proxy briefly
Corporate proxies and some VPNs block or intercept the reputation endpoints. If the message disappears with the VPN off, that is your answer, and the fix belongs with whoever runs the network rather than with your PC.
- 04
Look at the setting itself
Windows Security, App & browser control, Reputation-based protection settings. If “Check apps and files” is off, turn it on. Some tuning utilities and debloat scripts switch it off silently, which is a common cause on a machine somebody else set up.
- 05
Check nothing is blocking the endpoints
A hosts file entry or firewall rule aimed at Microsoft telemetry frequently catches SmartScreen too, because the names look similar. If you have applied a blocklist of Microsoft domains, that is the first place to look.
What SmartScreen is doing, and what it is not
It is largely a reputation check. Windows sends details of the file, including its hash and who signed it, and Microsoft answers based on what it has seen elsewhere. That makes it good at catching things that are already known to be bad, and it makes it noisy about things that are merely new.
Which is why “Windows protected your PC” so often appears over perfectly ordinary software from a small developer, and why a freshly released version of a well known program can trigger it for a few days. The warning is about familiarity. It is not a scan result.
The consequence worth internalising is the other direction. No warning does not mean verified. It means nothing was flagged, which is a much weaker statement than it feels like at the moment you are looking at a download you are unsure about.
We are not going to tell you how to switch it off
It is the most searched thing about SmartScreen and it is the one thing this site is not going to help with, which seems fair to say out loud rather than quietly omit. Everything here exists to make downloads checkable; a guide to turning off the check that arrives with Windows would be an odd thing for us to publish. If SmartScreen is failing, fix the failure. If it is warning you about a specific file, decide about that file.
Common questions
- What does “SmartScreen can’t be reached right now” mean?
- That Windows could not contact the service it asks about downloaded files, so it has no answer to give you. It is not a verdict on the file. The usual causes are no working internet connection, a system clock wrong enough to break TLS, a VPN or proxy blocking the endpoints, or the reputation check being switched off.
- Can I still run the file when SmartScreen cannot be reached?
- Windows will let you, but you are running it with one fewer check than usual, so it is worth replacing that check with another. Confirm the file came from the publisher’s own address and that its SHA-256 matches what the publisher declared. That is a stronger check than reputation anyway, because it is about the exact bytes rather than about how many people have run something similar.
- What does “Windows protected your PC” actually mean?
- Usually that the file is rare, not that it is dangerous. SmartScreen scores files partly on reputation, so a legitimate program from a small developer, or a brand new release of a well known one, can trigger the warning simply because few machines have seen it yet. It is a statement about familiarity, not a malware detection.
- Does no warning mean a download is safe?
- No, and this is the more important half. Reputation works both ways: something widely distributed can pass without comment. A missing warning means nothing was flagged, which is not the same as anything being verified. Checking the publisher and the hash tells you something specific about the file in front of you.
- Why does my own signed application still get flagged?
- Because a certificate proves who you are, not that anybody has used your software. Reputation accumulates as installs happen, so new signing certificates start from nothing and early releases get warnings even when correctly signed. Extended Validation certificates are treated differently, which is much of why publishers pay for them.
A check that does not depend on reputation
Reputation asks how many other people have run something like this. A hash asks whether the bytes in front of you are the ones the publisher shipped, which is a different and more specific question. Paste the SHA-256 of your download to check it against the installers we hold, or open the page for the program itself to see the publisher's own URL and the hash they declared for that version.