Hp a1600n gaming pc

If you can order from newegg, they might have an amd shellshocker combo deal in the next two days. But your budget is pretty low, and changing the motherboard will require a new windows coa. So for your budget, if you don't get the shellshocker deal, all you have is enough for a video card and power supply upgrade such as these:

http://www.newegg.com/Product/Product.aspx?Item=N82E168...
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

You can choose a different brand for the video card, but the sapphire gets good reviews and has no excessive noise issues.

What is a windows coa? And should I Get more ram also?

Your original windows installation only works with your geniune hp motherboard; there's a small bios string that id's it when windows loads. I've experienced this issue first hand; windows is around $100 for 7 home edition; craigslist might have one for less. You won't have enough for extra ram, but check craigslist anyway for ram deals. You might find 2 gb of ddr2 for $25. If you can order from newegg, the shellshocker specials are your best upgrade. The new onboard amd graphics should play your games at medium settings; here's today's special $280 before rebate including shippping: http://www.newegg.com/Special/ShellShocker.aspx?cm_sp=S.... Here's a new Lenovo pc that's $330 with coupon code: http://slickdeals.net/permadeal/70024/staples-lenovo-h4...

The shellshocker looks like a whole new computer. Does it have all parts in it or do I have to build it?

You have to build it. If you don't want to fool with it, go with a brand new system or the video card and power supply I recommended, along with 2 gb of ram off craigslist for $25.

I think im gonna go with the Lenvo pc up there or if I cant get a extra 40$ just get the video card,power supply and ram. Also is the Lenvo better for gaming or the shellshocker?

They're both about the same; the lenova has a quad core cpu but not the latest amd cpu with the graphics on the die. You can still buy a separate video card later; you can also wipe your hp hardrive after making a backup copy of your windows installation, and sell it intact to pay for part of your purchase. You might get $80-100 for it after reinstalling windows.