Googled cause: video card(ATI) driver version seems to prioritize GPU temperature over CPU temperature, causing cpu overheat before gpu signals fan to spin.
- Clean fan and heatsink with brush and blower.
- Uninstall ATI driver, unsuccessful... BSOD before reaching uninstall.
- Backup data, prepare for reformat and reinstall of Windows XP Media Center 2005
- Download Win XP MC2005 (laptop has license key anyway)
- Laptop refuses to boot using the downloaded disk, but it works on another laptop.
- Remove HDD and connect to usb. Make sure there are multiple partitions, one for the OS and another a temporary drive(FAT32). Attempt diskless install via: "Z:\I386\winnt32.exe /syspart:K: /tempdrive:K: /makelocalsource /noreboot" where z is the dvd drive is and K the fat32 partition. (note: DO NOT use sp3 installer, will give 'iaStor.sys' not found errors)
- Place back HDD in laptop. Boot and install winxpmc2005
- After XP, install ATI video driver and ATI Catalyst.
- Installation is stable although fan still doesn't spin while in XP. still investigating.