Upgrading computer, what parts to keep?

[Momokogo]

I want to upgrade my current computer, but I don't know what parts to keep. Also, I don't know how to find out what exactly I have, like for my motherboard and ram. I know I have a 2-256 sticks of ram and a 512, and my motherboard is AGP. I have a radeon x700 pro 256, and an amd athlon 2800+ processor.
How can I find out what else I have, without taking apart my computer?
Also, what pieces should I keep? I have about a 500 dollar budget.
Thanks

 

[^Mike^]

well you could search for your computer model number on google and find the specs if it's a brand pc>

 

[TRDCorolla1]

You can find out some info. from your Device Manager or download a utility software like Everest or Sisoft Sandra to view system specs.

If you have $500 to spend, get a new motherboard, CPU, RAM combo (just don't go all out nuts getting the best). Keep the rest of the stuff. You can probably squeeze in a new video card that supports PCI-express.