Sampson,
Thanks for your quick reply.
My motherboard is a Gigabyte 8IRXP ... it is 'meant' to be an overclock friendly board but it has problems with POST unless you flash the bios to the f9 release (which I've done).
My interest in overclocking is purely curiosity. I don't have a particular result in terms of gaming/application performance that I'm desperate to achieve. At the end of the day if I can't make it work for me then I'm not going to lose any sleep over it.
In terms of cooling I'm using a thermalright XP120 on my CPU and an NB1 on my northbridge. 2.2GHz gives me an idle temp of about 41 degrees - not antartic but enough so I'm thinking heat isn't my problem (unless you mean that the RAM chips themselves become too hot, in which case can you suggest a way for me to bring the temperature down?)
From what you've said so far I'm guessing my memory is the cause of the instability. I'm not sure what manufacturer it is but I'm fairly certain it's pretty much bog standard DDR. What threw me really was the result - i.e. the random virus message and the subsequent blue screen. I was expecting it to either work or not work but obviously it's not quite as simple as that.
What's the situation with modifying voltages? Is this likely to solve my problem or not do you think?
Thanks,
Mal