At first I would just get a BSOD ocassionally. Then NT would crash if I tried to do just about anything. At this point the system would always re-boot. It has now reached the point where just after disk initialization (the string of dots) I get a display of many colored squares for a moment and then the system re-boots.

I have tried a different power supply. I replaced both drives with the ones I removed recently (I was running out of space). I replaced the graphics card. I tried booting in the vga mode. None if this produced any change in the results.

As this is a fairly old cpu I guess it is probably time for a new mb and cpu and some memory to match. I would like to determine what has happened if possible.

Sounds like a RAM problem. Try a utility like Windows Memory Diagonistic (http://oca.microsoft.com/en/windiag.asp) to confirm if this is the case.

It doesn't appears like a RAM problem. More like a filesystem damage. You know how to fix it? Partition Magic helps; or any other partition manager that checks for fs damage. Anyway, OS could been lost some system files in the worst case.

You might try changing the size or drive location of your pagefile.

When you change it (always a bit larger) it deletes the old one, on the reboot and restarts a brand new one. Have been surprised at how many times that settled down a fussy NT 4 box now.

NT is notorious to be unable to purge its pagefile on reboot. Worth a shot.

Good judgment comes from experience, and a lot of that comes from bad judgment..... Will Rogers