Every time I give my PC a major task to do such as streaming an HD trailer, or installing a new game. The computer goes to a blue screen saying something like DRIVER_IRQL_EQUAL_NOT EQUAL something along those lines I cant really remember this is really annoying me as I have just spent £400 on new hard ware
Intel Quad Core Q6600 @ 3.00Ghz
4GB DDR2 RAM
600W OcZ Stealth Xtreme
Arctic Cooling 7 Pro
nVidia Geforce 8500GT
Seagate 250GB HDD
Windows Vista 64-bit
Have you set your RAM voltage to mfg. spec? This is a common problem. If you are running 2.1 or 2.2 volt RAM at the default of 1.8 set by most MOBO's you will likely get instability when you OC, even a little OC .
If you post your RAM details (make/model #) we can look it up for you.
if that does not fix it run memtest86 on the ram. And check your temps. Maybe the heatsink is not all tightly.
If undoing the OC fixes it then you have an issue somewhere with the OC settings. 3 gig is a conservative OC for the q6600 and it "should" work, assuming good cooling and proper tuning of all the settings, but no OC is a gimmie, you might have an unlucky chip. You have good components so 3 gig should really be doable with an arctic 7 I would think. Make sure the heatsink is making good contact, sometimes the pins don't stick in the lock position and the heatsink rises back up a bit off the chip.
If it isn't an OC issue then I would run memtest86 on each memory stick individually.
The Transcend Jetram I can find listed runs at 1.8 v, so the advice I gave above should not apply. However, all Transcend Jetram may not be the same and without a model number it is hard to say. Look on the box and see if you see a voltage rating. It will say 1.8v or 2.0 v etc.