After uninstalling games, they still take up hard drive space

[R97R]

So I've recently tried uninstalling a couple of games to free up space (in order to get steam to detect an installed game which came up as uninstalled, which is its own issue). Whilst they appear uninstalled, no disk space has been freed up. I have tried the following in order to fix this so far, unsuccessfully:

• Deleting the game folders in steamapps/common
  
• Checking my disk for errors
  
• Restarting Steam, and then rebooting my PC
  
  What else is there I can try? I'm at the end of my tether on this one

[ReBoot]

How do you check the disk space?

[R97R]

You mean how do I check how much disk space is left? I look at the "This PC" section of windows explorer, and have also checked it by attempting to install a game via steam, where it tells you how much disk space you have free

[ReBoot]

Ok, thats good.
Next, if you think that the game folder still uses space, delete it manually. If the game is uninstalled as far as Steam is concerned, deleting the game folder has no side-effects.

Well, almost none. Few (mostly old) games put their save files there. You might want to back them up. Assuming you care, that is.

[R97R]

I've deleted the game folder, still no change sadly. They're newer games (Oblivion and Skyrim), so I have save backups luckily

[ReBoot]

Then the space is used somewhere else (or you deleted the wrong folder, but you seem to know what youre doing, unlike many other posters). Get TreeSize and see what folders take up space.

[R97R]

Okay so for some reason after running TreeSize the space has now been freed up (both TS and windows explorer now showing ~100GB free instead of ~40). I'm not really 100% sure what's happened there.

As a side note, steam had also tried to redownload all of my mods for another game, which was taking up some space as well, and may have contributed to the problem.

Thanks for your help, @ReBoot!