Ignore him. He's babbling about apple being better than windows all the time.

hehe
If you don't know if your computer has Serial ATA, it probably doesn't.
Here's a good deal on a standard hard drive:
http://www.newegg.com/Product/Produc...82E16822144422
$100 for 250GB (at 7200rpm and 16MB cache, so it's a good quality, fast one)
And here is a 200GB hard drive (also good specs) for $90 shipped:
http://www.newegg.com/Product/Produc...82E16822144187