What games can my CPU run!!!

my computer is pretty bad: acer aspire e571...I went on acers homepage and said my computer can only support up to intel dual core 3.8ghz

My graphics card requires 400 watts or psu..

Sorry im not really a computer guy...how to check ur psu

To check your PSU you'd have to pull the side off your computer. There is supposed to be a manufacturer label that you should see that tells you the manufacturer, the number of 12v rails, and the wattage/amperage outputs for it for each rail. Now a days, to keep up with the newer hardware, at least a 600 watt with 18-24 amps on the 12v rails is required.

If your memory is DDR2 and your PSU is good enough, you could upgrade your system to an AMD or Intel quad core for $200, $250 if you need a PSU.

Sorry im not really a computer guy...how to check ur psu

The pentium D isn't actually an Intel Dual core like the E8400. 

My specs right now are:

Q6600 2.4 mhz, Asus P5KPL-CM m/b, 4 gig DDR2-8500 1066 ram, GTX 260 core 216, X-fi gamer sound card, 650 PSU.

Hey, since your video is PCI, your box would be even cheaper. A new CPU and mainboard might do it? What type of PSU and memory have you got?

Your CPU is what's going to really hold you back.

PCI

Im in to first person shooters...and Pentium D has 2 processors.