I have a game system set up (still using WIN98) that several games have been corrupted or incorrectly installed, I cannot reinstall them, setup says "Game in already installed please uninstall." But when I run Add/Remove programs or a manual uninstall it says "Can't find uninstall log." and quits.
Any body know a way around this ?

It might help to tell us which game it is.
You are going to have to find everything that the game installed and delete it. This includes items in the registry. If you don't know about the registry, be extremely careful not to delete anything unless you are certain of what it is. Click Start> Run... type in "regedit" (without quotes). This is the registry, but I don't know what to look for until you tell me what game it is that you have. :-P
While your in the registry you might as well look for folders called "gator" "cydoor" and see if you have spyware. This is where those nasties hide a lot of their stuff.

If I may add besure to back up the registry before looking around in it.
You may want to try the Demo of Registry Mechanic to help you out.