>Does anyone know of a good hardware diagnostic tool?
>
>About 2-3 times a day, I get Windows system error messages related to my video driver (ATI driver for a Toshiba laptop). Windows resizes the resolution down to 640x480, 4 bit color, and I have to reboot. When I reboot, I get the blue screen of death, and so I power down for a minute or so and then reboot. This started a few weeks ago. I can't detect any pattern to this.
>
>I don't know if the adapter is bad, or if I have a driver issue. The laptop is 7 months old. I pulled down the latest ATI driver, but it didn't make a difference. I'm doing searches on Toshiba's site, but wanted to ask if anyone knows of a comprehensive hardware diagnostic tool.

Superficially it sounds like a bad RAM chip in your display adapter. On a few notebooks the adapter is separate from the motherboard and can be changed or upgraded; most can't. Is it still under warranty?

Download.com lists a couple of hits when searched on "Diagnostics", at least one appears to be free to try.

SiSoft Sandra is widely used: http://www.sisoftware.co.uk/index.html?dir=dload&location=sware_dl_3264&langx=en&a=

I don't know which current version you'd need to stress-test your video, and/or which versions are free vs. non-free.