Thanks Mel. I had N360 V1.0 last year. I bought and installed a retail V2.0 this year, along with a bonus Norton Ghost 14.0. I have had various external USB 2.0 storage devices hooked up from time to time, but nothing external is hooked up when the problem occurs.
Sometimes the system runs for hours before the crash occurs. I just tried to run Norton Diagnostic Report, and the crash happened almost as soon as I started the diagnostic.
I'm running a clean install of Vista Home Premium SP1 on an ASUS M3A-H/HDMI motherboard with AMD dual core A4850E 2.5G CPU, 2GB of Patriot dual channel DDR2 PC 8500 RAM with three WD 500GB SATA HDs. Installed software includes MS Office 2000 Pro, Photoshop CS3, InDesign CS3, Adobe Lightroom 1.4, Adobe Acrobat 8 Standard, and Eudora 7.1.0.9 Paid mode for email. I'm using the onboard ATI Radeon HD3200 graphics with shared RAM and onboard sound.