Originally Posted by tube2k

Try seeing if InstallShield needs an update. Also, from my research, you may try renaming the InstallShield Folder, and go into your add/remove programs and see if ICQ got itself into there.

One more thing to try is to download ccleaner and clean the shit out of your system, the registry and everything (I use it all the time) and then try reinstalling after you clear your FF cache, etc.