I have a strange problem on my laptop. When I open any program, (Windows explorer, IE, Firefox, notepad) it keeps trying to refresh itself, as if the F5 key is pressed. The frequency of refresh is not fixed, sometimes its every 2 seconds, sometimes 10 seconds. If I open Task manager, Taskmgr.exe is continuously running from 0 to 100 and so on. CPU usage stays spikes at 100% and then about 25% and so on. Then all of a sudden, it starts behaving normally, only to behave the same way after some time. I checked if the f5 key is stuck, but is is fine. I checked the sfc Windows File Checker Version utility, and it did not find any issues. If I restart the system, then it works fine for some time(about-3 hours) and then same behavior.
I have tried doing a full virus scan(McAfee, trend micro), and it found nothing.
My Systems details ar as given below
Dell Latitude D630 5100 xp service pack3, 3 GB RAM
Any inputs to what could be wrong will be helpful