Things which are NOT causing the freezing

Software or Operating System- format and complete reinstall hasn't fixed the problem.
RAM- 2 different sticks tried without changing the results.
TV Card- removed it and it still froze. Also, now Vista BSODs on me before the login screen.
Overheating- she's perfectly fine after I restart; I don't have to wait for her to cool off before restarting
CD-ROM drive- removed it and she's still freezing