Hi Frank,
Try running them in safe mode and in diagnostic mode. The latter, if it
works, probably indicates a software conflict. If they work in safe mode,
it's more likely a video driver issue.
For Diagnostic mode, run msconfig from the start/search line and type it in.
On the general tab simply check the box, click apply/ok and reboot as
directed. This limits the amount of software loading at normal boot and
should eliminate any potential software conflicts.
For Safe mode you can load this either through the boot tab of msconfig, or
by selecting it from the boot menu by hitting F8 when the system first
loads. If the scans run ok here, then you more than likely have a video
problem.
If niether mode works, I'd suspect a hardware issue, possibly faulty memory.
Running the memory diagnostic tool may reveal if this is the issue.
--
Best of Luck,
Rick Rogers, aka "Nutcase" - Microsoft MVP
Windows help -
www.rickrogers.org
My thoughts
http://rick-mvp.blogspot.com