Are you using official Sumatra build?

Did you download Sumatra from official Sumatra website?
If not, we can’t help you because we didn’t create the software you’re using.

Uninstalling Sumatra

There are 2 versions of Sumatra: an installer and a portable version (zipped executable).

Uninstalling portable version

If you’re using zipped executable, the only thing you need to do is to delete SumatraPDF.exe.

Uninstalling the installer version

If you installed SumatraPDF by running official installer, you uninstall it like every other application.
On Windows 10 / 11:

What if the above doesn’t help?

What if you still have questions? You can use the forums to ask for additional help.
However, in order for someone to help you, you need to provide the following information:
To emphasize: if you don’t provide this information, we cannot help you.