If files already have been downloaded and an update is pending then check the updates\0 folder in the Firefox program folder and possibly the updates and updated folder in the hidden "AppData\Local\Mozilla\updated" folder.

• C:\Users\%USERNAME%\AppData\Local\Mozilla\

My C:\Users\%USERNAME%\AppData\Local\Mozilla\updates is empty and I don't have C:\Users\%USERNAME%\AppData\Local\Mozilla\updated

But somehow it still says "Restart to update Firefox". So there must be some other location.

C:\Program Files\Mozilla Firefox\updated seems to have something but it seems to be unpacked version of FF, not installer anymore but I have not yer run installer with admin privileges so I don't know how it could have possibly written there.

Edit: I also found I have C:\ProgramData\Mozilla-1de4eec8-1241-4177-a864-e594e8d1fb38 but there seems to be nothing interesting at the moment.

My C:\Users\%USERNAME%\AppData\Local\Mozilla\updates is empty and I don't have C:\Users\%USERNAME%\AppData\Local\Mozilla\updated

But somehow it still says "Restart to update Firefox". So there must be some other location.

C:\Program Files\Mozilla Firefox\updated seems to have something but it seems to be unpacked version of FF, not installer anymore but I have not yer run installer with admin privileges so I don't know how it could have possibly written there.

I also found I have C:\ProgramData\Mozilla-1de4eec8-1241-4177-a864-e594e8d1fb38 but there seems to be nothing interesting at the moment.

And there also seems to be C:\Program Files (x86)\Mozilla Maintenance Service\ with not much interesting.

My C:\Users\%USERNAME%\AppData\Local\Mozilla\updates is empty and I don't have C:\Users\%USERNAME%\AppData\Local\Mozilla\updated

But somehow it still says "Restart to update Firefox". So there must be some other location.

C:\Program Files\Mozilla Firefox\updated seems to have something but it seems to be unpacked version of FF, not installer anymore but I have not yer run installer with admin privileges so I don't know how it could have possibly written there.

I also found I have C:\ProgramData\Mozilla-1de4eec8-1241-4177-a864-e594e8d1fb38 but there seems to be nothing interesting at the moment.

And there also seems to be C:\Program Files (x86)\Mozilla Maintenance Service\ with not much interesting.

Quote: C:\Program Files\Mozilla Firefox\updated seems to have something but it seems to be unpacked version of FF

That is correct as Firefox creates the updated folder with the new version when the downloaded update is ready to be applied to prepare for updating on the next start. So you can delete this updated folder to prevent Firefox from asking to apply this update. You can check application.ini to see what Firefox version this is about.