For those talking about the power supply...everyone is correct in a way. 430watts should be enough, then again it might not be. It's not really the max wattage you need to worry about, but rather how much current you are getting for all your voltage lines. I forgot the numbers, but it is recommended to have a certain amp going to your 12V line (you could probably search an OC forum for the right numbers).
I am using DFI Lan party 4 Ultra D w/ AMD 64 3000+ OCed and 6600GT, 2HDs, 1GB ram and the recommended PSU was 480watts. I'm using a 450watt cooler master and it runs fine. I'm not even getting the recommended amount of current supplied to the 12V line (DFI recommends 26A, I have like 22A) and I have a solid computer.
But a few things to check:
1. Make sure your mobo has all the power supply connectors connected. My DFI board requires the 24 pin connecter, 12V connector (a square cpu 4 pin), and another 2x 5V (molex 4 pin connector and 3 pin fan connector). Actually, I probably have the 12V or 5V mislabeled, but the point is my MOBO is power hungry and requires all those connectors plugged in. So make sure you have all power connectors plugged into your mobo that you can.
2. RAM settings. Make sure you are running at the recommended timing settings/voltages and you could always have looser timings which would allow more stability. If you are OCing, then you really need to make sure your RAM settings are well tweaked.
3. CPU settings. Again, like RAM, make sure your settings are on the recommended settings. If you aren't OCing, make sure you have enough voltage, your LDT/HTT stuff is all correct, etc. Underclocking should be a last resort.
I recommend first above all other things, to get an OCZ powerstream 520Watt ATX 2.0 PSU. It might be pricy, but buy it from Fry's or something to test it out and if ti don't work, return it
