Video fades in layers

WinNT4 Workstation, SP4 (tried 5&6a), Asus440BX, Celeron433, 64MbPC-100, AGP video, Office97SR1 (triedSR2) & Sidekick95.

Once every several weeks, one workstation fades out toolbars, then starts to get this freakish blur going across it. I was always told that it was in Microsoft Word, but witnessed it the other day in other programs also.

It tends to lose toolbars in stages.

Antivirus definitions are updated religiously, changed memory, processor, video card, flashed BIOS, re-installed OS (including low level format of hard drive)…kicked at, prayed over it and the thing still won’t work.

What’s going on here?

I’ll try to give more details if you need them.