Bigmack, come on bro. You should know the motherboard he has won't support that card, much less his power supply.
Deepu_15, get the radeon hd 3870 agp. That's the most powerful graphics card that will be supported by your motherboard, as it has an agp interface.
Don't think they released a 3870 in AGP I'm pretty sure the 3850 was the fastest 3 series card released. If you are looking for an AGP card then I'm pretty sure the 4650 was the most up to date card released on that interface.
Please check with the motherboard makers website for compatibility . You could well need a Bios update.