I just installed a new HD in a an old HP Pavilion 8755c with Win ME on it. When I tried booting back up I got the message "operating system not found" on a black screen. I wasn't concerned because I knew the OS was missing as I had just replaced the primary HD containing the original OS and all files on it with a blank HD that I was going to reinstall ME on. However, the set of ME recovery discs I was going to use weren't being recognized. I'm quite sure I'm doing something wrong like not going into the BIOS at startup. I need a guide for this! Long story short I wanna by XP Pro and someone reccommended a OEM version from NewEgg would be fine. My question is, what does the XP retail offer that the OEM does not? Any other reccommendations would be gladly accepted!