I can't launch the game.

How did he get it uninstalled, though?

@TossingFRONK This is a great question. I tried everything and I am fairly tech savvy. I just refused to go to the registry edit options because that is always an unecessary risk in my opinion. Rather wipe the hard drive than make that one tiny mistake that can fuck your PC.

I got to delete the 50 gb folders in MutableBackup too.

You have to do a few things to delete everything and get your disk space. IT DOES NOT REQUIRE FORMATTING! You need to make yourself the owner of all of the files (main folder, subfolders, and files) in the security tab under properties when you right click the directory. You then need to deny/change some of the permissions of the SYSTEM administrator through that same tab. You should be able to delete then. If you hit uninstall it actually should delete 1 of the 3 (about 3 or 4) PSO2 folders that is taking all your space.