Hi, you are posting to a 6 month old thread. You could do better starting your own.
RE upgrade w/o frying.
Two major choices. You can keep the existing power supply (PSU) or you can upgrade the PSU. If you keep the current PSU you can do much better than your current integrated adapter, but you are limitted to low power, low end video cards. If you upgrade the PSU it only cost maybe $60 extra, but you need to remove the old one and install a new new. If you are handy tehn swapping the power supply is trivial. Just unplug he old wires and plug int eh new ones. 4 screws hld in the power supply and it's a standard size. If you open the case and are not going to move all those wires then go for teh low power video cards. Good news, low power video cards are cheap.
You have:
Phenom II X4-830 (D) 2.8 GHz (95W)
250 watt PSU
You can add a 105 watt video card, maybe. But don't overclock it. Say an HD6750 or 5750 (same card, different number).
You can add a lower power card, say Hd 6670.
Here is a ref on video cards, google the card +TDP to get wattage. You have about 200 watts available on 12V total, so you have about 100 watts left for video.
http://www.tomshardware.com/reviews/gaming-performance-radeon-geforce,3018.html
If you swap PSUs then you can put in any video card as long as the card is not too long to fit in the case.