Lock ups

[nIckEl101]

Look for abit of advice on what to look for, to try and pin down why my pc locks up when gaming, and i have to hit the hard reset button. It doesn't lock up consistently apart from when my g/f plays Sims 3.

This behaviour has only started recently, and seems to have coincided my g/f installing and playing Sims 3 (I really don't want to point to that as the point of my pc just freaking out lol)

The pc is about 2 years old now, and has been working perfectly for the most part

specs are as follows:

Intel® Core™ 2 Quad Q6600 Quad Core Processor(2.4GHz,8MB Cache,1066MHz)
Genuine Windows Vista™ Home Premium Edition
Aluminium ATX Midi Tower + 550W PSU - Black
PCI-Express Mainboard - SLI nForce 650i SLI(C55) - Intel Core 2 Duo/Quad-Core - ATX
4GB DDR2 667MHz Memory -( 4x 1GB )
750GB (1x 500GB + 1x 250GB) Serial ATA Hard Drive with 16MB Buffer
LightScribe Super Format 18x Dual Layer DVD Writer +R/-R/RW/RAM
768MB nVIDIA GeForce 8800 GTX - Dual DVI, HDTV, TV-Out

Steps i have taken so far:

Update All the drivers: mobo, gfx, hdd and windows vista.

I have downloaded Memtest that will run this evening when i get home.

Is there anything else that i can download to test components.

Any thing else i can look out for to indicate what may be causing it?

thanks

 

[rexehuk]

Virus Scan clean?
Spyware Scan clean?
Any overclocks?
Defragged PC?
Scandisk?
Windows Updates - Hotfixes caused conflicts?

 

[UKDTweak]

Have you checked your Event Logs after resetting from a lockup? There maybe a log that can help you pinpoint if there is a driver or hardware problem.

Could be your graphics not getting enough power, or a bad driver ???