Game doesn't work after moving...

I like to mess with my computer probably more than is good for it. A while ago I split my partition into two. I installed a couple games on the new partition. After a while I decided to merge the partitions back together. Unfortunately, this seems to have broken the games I installed on the other partition. I still have all the files, it just wont run. Is there a way to fix the game without reinstalling it? I'd think I could make a new partition with the same drive letter as the old one and move them back but I'd rather not if there's another way.

Oddly, Steam games don't have this problem. As long as they're in Steam's install directory they will work regardless of where I move my Steam folder to. This gives me yet another reason to think that Windows does not handle a lot of things in an ideal manner.

Edit the registry file(start>run>regedit) of the game and you should be fine.

Are all your games broken? The problem is registry entries as the previous poster mentions, in my experience the vast majority of games works just as well without them though.