Have you run Windows Update lately?
This just started in the last week, but when I log on to XP the time is either ahead by 4 hours or back by 4 hours. I have tried resetting it and have double checked that I have the right time zone chosen and that works for a day then it goes nuts again. I tried to sync it with different time servers and it always fails a connection. I am not having any problems getting on the net or using email, do I don't know what that is all about. Any suggestions?