is my system under powered?

Go back into bios and set everything to optimized defaults (always after bios update). As far as trying prime95 again, it depends on how brave you are.

Sorry to hear that. Maybe we will hear from Jonathan King soon.

If you can edit the title of your post to mention BSOD, it will help.

Really, there's not much we can learn with these dumps now. Every so often, the dump will blame something like the hard drive, or give a bugcheck pretty unique to CPU problems, but in most cases, the offending piece of hardware is identified with either a diagnostic tool or old-fashioned "replace and observe".

I'd say the problem is probably either the motherboard, RAM, CPU, or PSU. Remove all but one stick of RAM and see how the system runs (stably?). If it crashes, try just one other stick.

Also here are a couple of PSUs to consider, and you should. From what I read your current one is a great 600W, but is supposed to be 750W, and you need enough to give all your components good, continuous, and clean power.
Newegg.com - Thermaltake Toughpower Grand TPG-1050M 1050W ATX 12V v2.3 & SSI EPS 12V v2.92 SLI Certified CrossFire Certified 80 PLUS GOLD Certified Active PFC Power Supply

Newegg.com - Thermaltake Toughpower Grand TPG-850M 850W ATX 12V v2.3 & SSI EPS 12V v2.92 SLI Certified CrossFire Certified 80 PLUS GOLD Certified Active PFC Power Supply

We can try to help you find out what the problem is, but be aware it is a long drawn out process. It basically involves eliminating one problem at a time. Let us know when you are ready. The easiest thing to start out with is to run in an elevated command prompt (start button-type cmd-right click cmd and select run as administrator) in the command window that opens, type sfc /scannow you can copy and paste that if you like, but notice the space between sfc and the / if you decide to type it. It is a system file checker that will verify all system files. If everything is OK it will eventually reply that it found no integrity errors.

Go to Asus website and make sure all drivers are updated and update your video card drivers. Go to AMD's website, they usually have the most updated drivers there.

Next, ram is usually the most likely suspect. read this tutorial and follow it, Test with Memtest86+ . That is quite time consuming, remember we are testing both the ram and the MB dimm slots. So, there is a lot of testing. each test needs to be run for 8 passes (usually 6-8 hours) you can stop if you get errors and go to the next step in the tutorial. Let us know how it comes out.