420 watt power supply enough for an x850xt graphic card?
 

Is this enough power for an ati x850xt graphic card and with a 3200 amd processor?

Yes. 420 watts should power any system if it's a good quality PSU.

Care to give a more detailed specification of the system you are running?

AMD Athlon 64 3200+
DDR PC3200 512 RAM
PCI Express ATI x850xt
Soundblaster Audigy
1 harddrive & 1 dvd drive

The PSU is a thermaltake called TR2-430 W. Is it easy to install a new PSU? You just unscrew the back of it and add the new one in and connect all the power ect right? Is there any reformatting or hardware that needs to be installed?

You just switch them out, your computer won't notice the difference and you won't need to install anything.

Though, you don't need to. The PSU you have can easily power the system you're running and you probably have as much room as you could need for overclocking.

anything 400 and up and you're in the clear. I believe that's enough wattage to power a SLi board.

What he said.^^

I have a rig configured with two 6800 GTs in SLi, 3 200 Gig drives and a 420 power supply. Works flawlessly under heavy loads.

holy crap u got a monster of a machine Frylock...

but yeah i second the 420 being enough, out of experience mostly.. My friend's 7800 gt works well with a 400'er .. and my X300 works perfectly (tho its less i know..but i have a 370WT)