Yep, just do as the previous poster said... just use FDISK to clear out whatever's there now and create a new partition. Then use format to make it usable. See here:
http://support.microsoft.com/default...NoWebContent=1
Anyway, is there anything on the RAM (a sticker, or etched in, or otherwise) that tells what type and speed it is? You should be able to find all sorts of info on RAM by searching the Internet which could help you identify what you have.