Help knowing power supply output

[frdrcklim]

So here's the story, a year ago, we upgraded my computer. Everything was changed except the hard disk. Anyway, I'm buying a new video card: the 1 GB GeForce 9600 GT ddr2. I've had plans but I'm only buying it now. The problem is however my power supply. Since the power supply is an important factor for the video card, I need to know my power supply output. The thing is however, my dad lost the receipt a long time ago and I could not find the box for my power supply and I have no way of knowing the power supply output. My guess is between 300-500 watts. The recommended is 500 watts for this GPU. Any ideas on how, I would find out my power supply output  ? Please reply immediately. Thank you  .

[wouanagaine]

You should have a sticker on your power supply, if it is not visible, open your PC, it should be on it

[Kitsune]

^ Exactly. Also how big is your monitor? It might not need that much v-ram.

[frdrcklim]

I actually found that out just a while ago. I never noticed it had details until I took my computer off but thanks anyway wouanagaine  .