AFAIK, if you see it there it means that it's still in the registry. But I could be wrong...
Have you tried restarting your PC yet?

Edit: try CCleaner if all else fails...

I haven't restarted yet, no. I guess the only thing left to do is to do that and then try CC Cleaner.

Yeah that's kind of my last resort. Even if I install galaxy to its own Partition I assume Galaxy still let sme install games on other drives?

Sure, you can change the game installation path in Galaxy settings. Or even better, use the offline installers.

Yeah it seems like I'm just SOL. Even CC cleaner didn't fix it. it did find some registry entries to fix but it still keeps trying to install to an E:\ that doesn't exist. This is weirdly baffling but this seems more like a me issue (except that the installer should definitely let you install to a new drive). I guess I'm stuck with offline installers instead of having a fixed library like steam I can just keep my games in.

Did you make an E:\ partition?

Are there no advanced install options to choose where it installs? I installed mine on my E: intentionally in a folder called !Galaxy (so it goes to the top of my games folder) the ! can break some things for certain programs (FFVII mod manager can't find my installation folder in !Steam) but I was able to do that with no problem.

Are there advanced install options for you? Any button anywhere in the install process that isn't "Next" is worth a click.

A little bruteforcing, maybe. Connect a thumb drive and assign it E:\, install Galaxy on the thumb drive, then uninstall again. Hopefully that clears all remnants of the old Galaxy install that make it default to E:\ and let's you do a fresh install in a place of your choosing.
Unfortunately, if the installer detects an existing Galaxy installation it defaults to that location in order to update the existing client. Which makes sense but creates a huge problem if that location no longer exists and you can't clear the leftovers in the system that fool the installer into update mode.

Forget about galaxy - it's more trouble than it's worth.

If you want to download your games, just use the normal offline installers. ( :

So half-assed programming from GOG again? This should come as a surprise to no one. It should be entered into the bug reporting system so they can hopefully one day tell us they'll fix it only to let it fester for 4 years before fixing it by accident with another fix that breaks 5 more important features.

No, this is a pretty common occurrence if you lose a drive due hardware failure. I've seen this way too often to fault GOG for it.

I'd actually say that it's a problem with the OS because it doesn't provide solutions to remove program leftovers cleanly in case of data loss.

If someone else encounters this problem. Installing GOG on a temporary usb drive before uninstalling it properly did the trick for me.

But please GOG, I see threads on this problem from 2016. I'm sure it's simple to fix in your installer. Keep your default location but just ask the user before trying to install Galaxy and it's ok. Even if a small number of clients are affected, **not being able to install galaxy** surely must be a problem to your marketing team or executive board so go tell them this so they let you take time to fix this issue, it really gives you a negative image.