iTunes Program Problems

I recently tried to add an iGame to my iTunes program from an outside file source and while iTunes was trying to add it, the program stopped responding–and so I did like anyone would do and ended the program. When I tried to open iTunes again, nothing happened. I tried all the shortcuts I knew and also going through and clicking not only the ones in the start menu, but also the .exe file itself. The only thing I have found is that when I “open” iTunes, it shows up in the Task Manager processes, but does not open up as an actual running program–only in the processes taking up CPU space. I have tried some system restore, and re-installing iTunes a number of times, and also have run some various spyware/adware/virus protection programs with no luck. I cannot get it to open up–does anyone have any ideas? I really don’t want to have to completely re-format my HDD, because that is a process I hate doing. Thanks.