Need help upgrading an HP computer

I recently got this comp and i was wondering if anyone can recommend any good parts for it:

I was planning on salvaging parts from my old comp, but it seems like it’ll be more complex than i thought. For starters, my old graphics card won’t run on anything that doesn’t have a PSU with a minimum of 400 wats. Moreover, the video card that is installed in my new comp is a chipset (Intel® G33/G31 Express Chipset family ), which i don’t have any experience with.

I’m assuming i’ll have to upgrade my psu, but i’m really not sure where to start. At the end of the day, i just want to be able to upgrade my videocard to something a little more powerful. Specifically, something that can handle games.

Can anyone help me out?

My specs:
Pentium® Dual-Core CPU E5300 @ 2.60GHz
6gb RAM
Windows Vista 64-bit
ntel® G33/G31 Express Chipset family
PSU 250 wats

My old graphics card:

FYI, my old computer is now a giant brick. I didn’t have a choice, but to buy a new comp.

Well your new PC has a crappy integrated video. Get a better PSU (400W or more) and use your old VGA.It’s way better than that Intel thing.

Yeah, thats the plan. Do you know of any good ones i can use? I’m looking for anything between 450 to 500 wats for my the PSU. Unfortunately, The case of my comp doesn’t look like it can support the kind of PSUs that i usually see on newegg. The one i have looks like it’s an Athena unit. There isn’t any room for a power switch, so i’m pretty sure it’s gotta be the other kinds of PSUs that has a red toggle on it.