What should I upgrade on my computer?

I have a Dell Dimension E520, it has a 2.8GHz Pentium D Processor, 3 Gigs of Ram, a nVidia PCi-E GeForce 7600GT Graphics card, 300+GB Hard drive, Windows Vista 32-bit OS, I keep it Spyware and Virus free. I thought I was good to go with any game made and well I recently bought Crysis and, lol, I have to run the graphics on low to play smoothly. So, now im looking to upgrade to play the game on high with no problems. Im sure im good on 3gig of Ram since thats all my Windows Vista will let me have anyways (Had bought 4 Gigs but the system only read 3). Should I upgrade my processor to Dual Core or get the newly released nVidia GeForce 8800GT? Which one will better increase my performance? I plan on upgrading both later on after christmas but I need to know which one will I benefit more from now? Thanks.

What should I upgrade on my computer?antivirus software

I say upgrade your to a dual quad core processor. But your graphics card and processor are not the only things you need to upgrade. If you want full functions with your game you have to get a good SSD hard drive like raptors. The hard drive is the slowest part of your computer so you want the fastest hard drive you can get.

What should I upgrade on my computer?computer virus

sounds like I'M the one that has to upgrade lol

you're all set. buy a mac with that quadcore if

you're looking for the most powerful tower
I would upgrade your video card or shut down any programs that you do not use when booting up.