Sorry I have so many XP issues still, but unless there's another XP site like this one, I only trust you guys.
In 2006 I purchased my Dell XPS M1210, preinstalled with Windows XP Media Center Edition 2005, OEM disc included. Since then I installed it many times over on the same and another hard drive, within this laptop. The last time, I had a problem. I lost the cd sleeve with the COA on it, and the sticker beneath my laptop is worn away. I can't tell 6's from G's or 8's from B's. I called Dell, and after some playing-dumb and cooing like a lost little schoolgirl, I got the guy to NOT charge me $50 for generating a new Key for me. I only had to pass a test of reading off other numbers to prove I have the actual disc.
Now, I am trying to install it again on a friend's hard drive, that is currently within the hot swap bay of my [insanely faster] rig. Perhaps I don't understand OEM's as well as I thought. Why can't I activate this one now with that key? It says it's not authentic.
It is a 2.5", so should I just pop it inside my laptop to appease it with Dell hardware?
(Before anybody says it, his dual-core 1.73GHz 2GB ram Sony Vaio can't handle 7, sadly...)