I'm not looking forward to Windows 8. My dead machine was running Windows 7 which didn't give me much trouble and had 4 gig ram, though it was already 4 years old.
It will be several months before I can afford to get anything though, hopefully I can get something before summer's over.
I wish people would just stop demonizing Windows 8. I run 7 on one, and 8 on another computer. The metro interface is quickly gotten rid of, and then it's like a Windows 7 Service Pack.
There's absolutely no fucking reason at all to complain about getting Windows 8 when buying a new computer.
Honestly you don't even have to get rid of the interface. Just spend about 10 mins going thru the tutorial and you'll get it. I'm running Windows 8.1 via Bootcamp on my Mac and it's not bad. It's basically Windows 7 with an interface skin.
It does feel disjointed though, with Metro Apps trying to coincide with standard Desktop apps.
Microsoft needs to work on it so that it can resize Metro apps if you want, or at the very least add some useful options to the Start button rather than just taking you back to the Metro Tiles.
You can use 3rd party utilities like some of what Stardock offers to get around these limitations though if you *must* have the Windows 7 interface.
$500 isn't going to get you a whole lot of PC. J.Allen's link is a pretty good option, probably as good as you're going to get with that budget.