Run Time 5 Error

I have a number of machines with Windows XP (both home and pro) and Works 2002. When they leave their machine for more than five minutes they receive a run time error 5 when they get back. I thought it was conflicting with our transcription software but I now have a user that doesn’t use transcription experiencing the same thing. I have turned off all the power saving/screen save functions. Any ideas would be much appreciated!