Thankyou antagram for the advice, it doesn't seem daunting at all. I have already tried reinstalling windows 3 times and updating drivers for graphics cards and motherboard.
I have also tried ten different physx drivers and numerous versions of directx.
I will try updating the audio drivers from your link, and check that i tried your recommended motherboard and chipset drivers, but i did download directly from the asus website so think i have tried that.
Thankyou for the helpful post though.