Not too sure if theres a way of finding out using any software, but you could take a look at the power supply. It will have a sticker on it which states the complete specs of the unit, including the total wattage and the wattage on each rail.
goldeagle2005
Finkus Stinkalotus
1,500 posts since Jun 2005
Reputation Points: 67
Solved Threads: 45
Yes, your PSU is a 500W one. The rest of the numbers tell you how much current is available on the different rails. it's38Amps on +5V, 17Amps on +12V...etc etc etc.
So, I'd say you're good to go for a new video card. Which one did you intend to get, by the way?
goldeagle2005
Finkus Stinkalotus
1,500 posts since Jun 2005
Reputation Points: 67
Solved Threads: 45