In addition to what torrentg said...
I'd be pretty surprised if you don't have yourself at least one hardware issue, and maybe more. A couple of those dumps are also suggestive of software symptoms, but
they're in the minority. Suggestions for trying to resolve or at least identify hardware problems:
1) Update your BIOS.
2) Update all hardware-related
drivers (NIC, chipset, video...).
3) Don't overclock.
4) Ensure adequate cooling.
5) Run a few hours worth of memory diagnostics.
Software:
6) Update or remove this Comodo firewall
driver (and the rest of Comodo with it):
Image path: \SystemRoot\System32\
DRIVERS\cmdguard.sys
Image name: cmdguard.sys
Timestamp: Sat Aug 22 01:05:30 2009 (4A8EB7BA)