Buying a new power suply

hey every one. I need to buy a new powersuply. My friend brought a tool over and it pluged into my usb and it says that i need 29 % more power than i already have. my current power suply is a open and it came with my case when i orderd it. i cant find how many volts it has. has any one else had to buy a new power suply and if so what shouldi get? 3 hard drives 3 fans 8 usb 2 ports 4 used all the time, g force 7800 and it plugs into the power suply, and 2 dvd drives. im going to guess that my power suply is 200 v because for some reason i remember that.  Buying a new power suply
if u can spend 100 bucks on it heres a good onehttp://www.newegg.com/Product/Product.aspx?Item=N82E16817256008 Buying a new power suply
Thankyou very much, If i put that in will my motherboard be able to handle it? where can i find max wattage information about my mother board? Darn 99$!? the one i got was an extra 130 ontop of the 200$ case! what a great price. 
what kind of computer do u have, prebuilt. list the name and model #.
Intel 865pe chipsetCPU; Intel Pentium 4 cpu, 800MHZ  Chipset; Intel 867pe + Ich5Main memory : ddr dimm x 6Graphics: 8x agp slotForm factor; ATXAX4SPE series aopen motherboard. that is all. 
yeah the psu is fine, agp huh ?
3 1/2 years old yea.. starting to regret that tho. but not a single problem playing anything hi quality. oblivion works fine im happy :D
yup all that matters is ur having fun. iam having probelms getting a new psu and a new video. i got like 150 to spend for both total. waiting for any price drop but guess iam a havae to go with the 7600GT :)