What is the material on computer covers when you buy a computer?

Help me buy/build a gaming computer on a budget!?

• Ok, i used to be going to school for computer networking and stuff. But i hated it and quit, now 5 years later ive found what i want to do, personal trainer. But for the last 5 years, i havent opened up a computer or checked em out or anything. So although i used to know the in's and out's, im severely rusty now, and need some help. Ok, i want a budget computer, but i want it to be upgradable, heavily. I dont have alot of money currently, BUT i would love to upgrade over time. So im looking at a really good mother board, and going from there. Im a little out of the loop, AGP is what i used to use for my video card, now its PCI-e. THere are new processors out now. Back when i was building em, there was just Intel and AMD, you bought a board for either, simple as that. Now those companies have duo and quad core processors, do they require specific mother boards? Or can i buy a high end mother board, but in a budget processor, then 4 months down the line, buy a beast quad core (same brand) SLI, i want to have a motherboard which has SLI compatibility, so that i can throw in a beater budget card to start, then, like the processor, few months down the road, throw in 2 beasty cards. Memory, well its gotten cheap, i saw a sale on newegg yesterday for 2gb's of mem for 46.99, no shipping, and i think it was corsair. As far as i know, hard drives are the same really, same with power supplies, and the towers are just as fancy as ever. Im not worrying about monitor/keyboard/mouse/etc. right now. Please, dont tell me to just save and get it at once. I dont know if i will necessarily be able to upgrade it, if ever. I just want my options open. (chances are i can upgrade it at some point, but i dont know when, and im sure as hell not waiting a year for a new good computer to play games on.) Im only looking to play WoW right now, well. The computer i currently have cant run it very well at all (its actually under minimum required specs, but i installed anyway, and ran it. It ran with everything turned down/off, but was still choppy) and since the new expansion, i dont have the hard drive space on my laptop to even install it. But ive been wanting a new computer for awhile now. Soooo in short. I want a desktop, which i can buy or build, which has a really really good base for upgrading (new Proc, new video card, more Mem, etc.), so i can keep semi up to date for years to come. (yes i know in the tech world, something 6 months old is obsolete, just go with it) i am looking to spend total, on the desktop, (Tower, Power supply, Hard drive, Vid card, Proc, Memory and Dvd Drive (onboard sound)) about 400-500 dollars for now. (if i missed anything vital, add it in/let me know)

• Answer:

  Windows XP and Vista are good ones. To upgrade XP, I think you have to buy a CD. But with Vista, you can do a thing called Windows anytime upgrade. Vista costs more, yes, but you could buy the cheapest Vista, then when you feel like it, do a windows anytime upgrade to Vista Pro. Anytime upgrades cost you, but of course, you can do it "Anytime" you feel like it