im experiencing the same problem .
after a long search on the net .
i found that your computer freeze because these following prob :-
1) Maybe your registry is messed up . i cant find the real registry cleaner that really helps .
2) Your driver may be wrong
3) A virus perhaps ? if u're using free anti-virus , try and get another one with license code . u can get the license code on the net for free .
if anyone can help me . please reply as well coz im having the same prob as NightCloud .
My specs :-
: Pentium D processor 2.8Ghz
: 2.5Gb Memory RAM
: NX7300LE TD256EH Nvidia GeForce Graphic Card
: Windows XP Pro Sp 2
: 80Gb Hard Disk if this helps
Well, I guess lots of people have the same problem and dat includes me. I juz installed a x16 PCIe Nvidia 7300 LE 256mb Inno3D card into the PCIe slot. After I on com, aero was enabled in my Windows 7 Ultimate 32-bit but after like 10mins, computer will hang. Or should I say after I start a 3D app(Online Games etc. Blackshot), it will freeze. Also, if I resume to my onboard graphic(SiS Mirage 3), it will not hang, it is just that aero will be disabled and the graphic will be really terrible espacially for gaming.. So what I guess was that it was the PCIe card (I bought a second-hand PCIe card) that has problem and I am going to have it for an exchanged soon. I will come back here to tell you about my results once I exchanged for another one and install it into my PCIe slot.
-EDIT- Oh ya, it can't be the drivers problem as I have installed the latest driver tons of time. (Uninstalling the card+driver and installing back again) Apparently, it cannot be the OS problem as I reinstalled my Windows 7 Ultimate 32bit with Windows XP PRO SP3 32bit, Windows Vista Home Basic 32bit and back to Windows 7 Ultimate 32bit again.
Registry can't be the problem FOR ME though, cus I downloaded a few registry cleaners and fix that already however, problem still persists.
I reinstalled Windows so many time which means everything is deleted and installed again so even I have virus, they are deleted too.
So, once I have my PCIe card exchanged and replaced, I will kip u informed. Good luck on me and you. ^^ Oh ya anyway I am juz a 12-yr old kid.
-Update- Oh ya, just want to know if ur graphic card is just installed into ur com and have u installed any other graphic card in the past. Please reply cus it might be useful for both of us.