[andrewas]

a comptuer made in the last decade without a flash bios? unusual. all award bioses withing that time are, and so is every other brand ive ever seen. id check the manufacturers website and make sure if i was you. (if you were told this by anyone working for PC world id bet you they were wrong)

on to other things.

firstly - think back to when the problem first started nad try to remember what you changed about the machine around that time. frequently some seemingly innocent application or peripheral can de-stablise the whole system.

try scanning for viruses. try upgrading your cooling - although starcraft probably woudnt be crashing the computer in this case. double check every connection in the computer. dont just look at them, physicaly remove and clean each component in turn. (NB - CAREFULY!) .if your computer has been running hot for a prolonged period (and athlons tend to), the chip may have been physicaly damaged. switch out components with another machines and see if you can isolate what is breaking. have a look through the startup files and look for anything odd. re-install your os (and i woudnt recomend using anything lower than win98 these days). get an air duster and remove the dust from the motherboard. that stuff can in some cases conduct sufficient electricity to short the motherboard and crash the machine. also, if you have a lot of drives and other peripherals, your PSU may be insufficient to drive them all. this is especialy common with the rise of usb. it should be 300w minimum with an average setup, rising to 450w with a couple hard drives and a modern graphics card.

thats about everything that occurs to me off hand - and tends to cover most problems in any case.