can my system take this??

Please calculate your power supply needs:
Go to:

http://extreme.outervision.com (Power supply calculator)

and add one Hard Disk, one optical drive, video card and CPU, use high end motherboard,
calculate Watts and divide by 12 to get amps. Add 2-4 amps for safety.

Compare to your power supply 12v rails.
Combined should not exceed requirements.

Max power output on 12v rails: look at box, subtract 3.3v + 5v maximum output from total
wattage of PSU and divide by 12 to get maximum amps on 12v rail. Should be higher than
requirements. That's why we add 2-4 amps.

See this PSU 101:
http://forumz.tomshardware.com/hardware/PSU-101-ftopict...

Top Tier PSU:
http://www.xtremesystems.org/forums/showthread.php?t=10...

Exhaustive PSU review:
http://forumz.tomshardware.com/hardware/xbit-labs-psu-r...

Your CPU will be where the door starts shutting on that subject.
But if you plan to do a all over upgrade in the future, the 8800 would be a good purchase as it is transferable. If you aren't planning on it for a while - not worth it imo  

One thing you didnt mention is your resolution. If youre anything smaller than 1600x1200 then go for the 8800gs. Itll provide close perf to the gt, requires less power(probably be able to use your current psu) and youll be dx10 compatible with good fps

I second the opinion based on a near future upgrade or not. If you aren't going to upgrade now then don't bother with the 8800 series, just get a 7900 or 1900 series card and save your money (maybe another gig of ram too).

i wanted to know that if i buy a 8800gtx and also a psu which can support it, what will happen. i mean will it create a bottleneck with some other component or not and will it work in its full potential or not.

In short, no. That video card is a monster. I'm not sure if I entirely agree with the study done on it by Tomshardware, but they said that you basically need the fastest current CPU (which happens to be a Core 2 Duo @ 3GHz+) for that card to work to its full potential.

Like someone posted earlier, it's not worth it for you to get the GTX unless you plan on upgrading your system soon. Get the GS as that would be less bottlenecked by your CPU, giving you similar performance for less price and some power savings.

Just from the looks of it your psu isn't strong enough. Nvidia recommends a 550, I think, minimum for the 8000 series. So as far as recommendations, go with PC power & cooling or Mushkin. Your CPU will create the bottleneck in your system. Like others have stated, if you don't plan on doing multiple upgrades now then go with something cheaper like a 7900 GS or 1950 pro. And as asked before, what res is your monitor?

i wont be upgrading for now. the only thing i will be doing will be adding 1gb of ram and buying a UPS. If i will be buying this vga card then i will also be buying a psu aswell. i am and will be running at resolutions 1600x1200. if i buy this card and assuming that i will buy the psu for this card, how much performance loss will i have.

Heres a link that will show how the cpu effects the 880 plus other gpu's. http://www.bjorn3d.com/read_pf.php?cID=1005 If youll notice, its not only the 8800 thats effected by thre cpu. Also the cpu in question here is waaaay better than your current one. That being said, you will enjoy improvement or best solution for fps using the 8800, tho itll be very bottlenecked by your cpu. Then again, you will already have the currently finest gpu made, and any upgrade to a new system(cpu/motherboard/ram) will show immediate results. Dont expect miracles using that cpu/system, tho this is your best gfx solution. My suggestion would be to wait til the ati solution is out, check for price reductions, and then go for it.