That computer's pretty outdated man...You'd also have to worry about what kind of power supply they put into it...the wattage and efficiency.
If you put too many upgrades in, I doubt it would take it.
For future reference...HP/Compaq media center XP machines are pretty awful in the specifications department...and the OS...And the crapware on the system when you get it
In short, I wouldn't reccomend upgrading at all if you can afford a new machine for about 500 bucks, a budget machine would run better than what you have...
But that's besides the point.
To upgrade yours:
RAM 2GB 2x1GB 74.00; http://www.newegg.com/Product/Product.aspx?Item=N82E16820231039
Video Card nVidia 9400 GT...Minimum...50.00; http://www.newegg.com/Product/Product.aspx?Item=N82E16814150488
Just waiting for that PS Vita to come out so I can play some full featured games on the go with that beautiful screen and control scheme...
