I have a similar problem, I think I have tracked it down to the 'Intelligent Background' service. If you look in 'Administrative Tools' on the Control Panel, click on the plus next 'Event Viewer', and then click on 'Services' from the sub menu. If it is the same problem there should be a sprinkling of red circles with crosses in with the explanation'Intelligent Background crashed on startup' or something similar. I have not found a way round this, but like you I only got this trouble after installing Norton 2002. My home system works fine though and that is running Norton 2003. Sorry to not be much help.