Like the topic says. Galaxy 2.0 is showing 63 games under the "Installed" section. All the wrong ones are from Steam. Some are old. Some are quite recent.
In reality I currently have 9 games installed through Steam plus 3 from other platforms, which means 51(!) entries are wrong.

At first I thought that maybe those wrong entries were some old files from the times when I was only using an HDD for games, but some titles were installed after I bought an SSD.

Anyone else encountered this problem? Is there a way to fix it?

EDIT: Deleting leftover files from the Steamapps folder does not seem to solve the problem.

Found a solution:

Starting to download a game from the list and then stopping the download(through the "uninstall" command in Steam library's context menu) removed unwanted entries from the Galaxy 2.0 client.

Hopefully, people with this problem will stumble upon this thread.

Hi.

This worked.

My scenario was a Uplay game bought on steam. When I re-imaged my windows, I did not install the game again, but Uplay still picked it up as installed, thus did GoG 2.0 as well.

Your approach removed it from all 3 platforms.

I hope they implement a better way of removing non-installed games as this is a pain if you have a large library.

keep your windows registry clean from old removed games and you won't have this issue. steam plugin specifically reads your registry entries to see what is installed.