A win 2000 pro pc with sp4 128 mb ram
The problem is this : The size of swap file automatically keeps on increasing even when no application is running.
The system is on a LAN with TINY personal firewall running.
The size keeps on increasing and when the total memory size ram +swap reaches near 320mb (when system starts memory consumed is near 95mb and even if no application is run it takes about 25 min for that size to reach 300mb) the screen becomes garbled with colored lines on it and a sec later the system restarts.
I checked with avg antivirus---no virus found
MS Anti-Spyware--No spyware found
Nothing unusual in HJT logs also.
Though sometimes it gave an error in Lsass.exe and gave a dialog that system will shutdown in 30 sec. (OS was patched for blaster worm and dcom was also disabled)
Checked for all the running processes but found nothing unusual.

Had to reformat and reinstall the OS because the problem was not allowing for any work to happen.

Does any one has any idea what would have caused such a problem.