Upgrading old PC for friend

I have an old HP Pavillion a1530n that I got for free and I am thinking about dropping a graphics card and some memory into it to make a gaming computer for a friend.  Any suggestions on what to get?  I'm not looking to spend much but just throw out some numbers.

here are the specs

http://www.newegg.com/Product/Product.aspx?Item=N82E16883107089

Its got a 300w power supply in it by the way

Well, you'll need to upgrade the power supply, maybe 500w with 80+, put in a small SSD and it'll speed things up too!  Finish with some additional RAM and go for a mid-grade GPU.  What's your budget?

Maybe $150 or so, depends on how much money he can round up

OK, not much to work with, but you already have lots of parts to work with.  Check this out:

http://pcpartpicker.com/p/wrd9

Four times thr DDR2 memory, decent GPU for the price (I had one from ASUS), and 500watts of 80+ certified power!  :]  If you round up some more shekels, I would put it toward a larger HDD.

Hope this helps.  VL

Well I have an extra 160 gb IDE hard drive in it for media storage right now and I'll probably use some different memory because the motherboard has a maximum memory speed 667 MHz or will it just clock its self down?

It should just clock itself down, but I would see if you can just get the 667 Mhz for less $$.

omg man i had some ram i coulda sent you but i traded it for drugs i had 2 4g ddr2 sticks. but that definitely needs upgraded, maybe the xfx 7750? that whole thing's pretty outdated i mean so it's gonna be pretty rough.  http://www.newegg.com/Product/Product.aspx?Item=N82E16814150612 unless thats too much to even spend. i'd do 4 or 6g of ram, 7750, and you could probably throw in a tiny ssd for the os to make it way fast. the psu could probably handle that but id keep upgrading in mind and maybe getting a cheaper gpu.

eventually that thing could shape itself into a pretty decent computer.

I was thinking about going with this for graphics http://www.newegg.com/Product/Product.aspx?Item=N82E16814161427

and this for memory because 4gb is the max amount and 667Mhz is the max speed for the motherboard  http://www.newegg.com/Product/Product.aspx?Item=N82E16820226088

Theres some other memory but this is only $4 more so I figured why not