Doing all that shady stuff like installing the Windows 2000 patch and setting the game to 2000 compatibility mode is just going to gum your installation up more. The focus should have been on trying to extract that compatibility toolkit thing from your system. If things seem broken, try using CrapCleaner's uninstall program to remove things. I don't think I've ever used this toolkit, so if it's something like DirectX that simply doesn't want to be removed, you probably have to research what sort of tricks people have online for getting it out of your system.