Strange Bigfish games problem

I have a strange question. I have a game called peggle. At one time it was installed on my pc for months with no issues. I uninstalled it since I no longer played it, that was a few weeks ago. I decided to reinstall it, what can I say it's fun. I used the same install file as before, I have it backed up on disk, and yes it has a cracked .exe, don't flame me please. Anyway now when I click the icon to start the game it deletes the .exe file inside the program folder. Even if I don't use the cracked .exe it still deletes the original .exe file. Anyone got any ideas? I even tried downloading a whole diffrent peggle game and it does the same thing. I can accept losing the game, but I don't want anything to be wrong with my PC like a virus, worm or anything of the sort. Thanks in advance.