# Windows says "unknown publisher" when installing

> Why Windows SmartScreen shows "Windows protected your PC" for the SellyPOS installer, how to check you have the genuine file, and how to continue.

Source: https://sellypos.com/help/troubleshooting/windows-unknown-publisher/
Updated: 2026-10-05

When you open the SellyPOS installer, Windows may show a blue box titled **Windows protected your
PC**, naming the publisher as **Unknown publisher**.

## Why it happens

Windows SmartScreen names a publisher only when the installer is signed with a code-signing
certificate. SellyPOS's installers are not signed yet, so SmartScreen cannot say who made the file.
It is a warning about the missing certificate, not about anything the installer does.

## Check you have the genuine installer

- Download SellyPOS only from [sellypos.com](/download/). The file comes from
  **dl.sellypos.com**, and its name starts with `SellyPOS-` and ends with `-setup.exe`.
- If you received the installer any other way, delete it and download it again from this site.

## Continue the installation

1. In the *Windows protected your PC* box, choose **More info**.
2. Check that the app name is the SellyPOS installer you downloaded.
3. Choose **Run anyway**, then continue with [installing SellyPOS](/help/getting-started/install-sellypos/).

> **If your antivirus removes the file**
>
Some antivirus software treats any unsigned installer with suspicion. Download it again from this
site, and if it is removed again, [message us on WhatsApp](/contact/) and we will help.