hey russ mate,
you got your system from novatech didn't you? If so, I would have thought it would void your warranty with them, however, that does not mean that they will know you have done it
.
When you overclock, the only evidence that you have done it is your BIOS settings. If anything does go wrong, you can (please note that word, I'm not saying you should
) reset your BIOS and claim ignorance, and they would know no different.
There are 3 things that you should do before you even consider overclocking though:
1. Check your current temperatures. Download HWMonitor from here, it will tell you what temperature your CPU is currently running at. Either type up what the results were, or screenshot them and post them up. If your CPU is already running too hot then you won't be able to overclock without first getting better cooling
2. Do you have an aftermarket CPU cooler? If you have the stock Intel one, you will not be able to overclock very much at all, not enough to make any real difference at least. You will be needing an aftermarket heatsink. It doesn't have to be anything big or expensive, even a cheap one is better than the stock intel one
3. Check that you are able to change the settings in the first place. If you go into the BIOS when your system boots up and are able to change the CPU frequency CPU voltage or the CPU multiplier, then you are able to overclock