I delete it, next time I boot it is back

I have a touchy problem. A member of our exec staff brought me his personal PC which has been used for porn surfing by his teenage son. The problem appears to be a file called “My Hot Porn.exe” which I have removed over and over again from the Windows System dir. Every time I start the computer it re-appears?? There has to be a reference to it somewhere so it will reload but I can’t find it. Anybody who can give me some ideas of where to look is a GOD!!! I need to get rid of this darn thing andmove on. You know how it is when the VP brings you a project!!

Thanks,
K