I have windows XP pro installed on my system, I'm needing to reinstall it on my system, but the only thing I have is an upgrade CD. Can I reinstall Windows XP with an upgrade CD? (remember I already have Windows XP Pro installed on my PC). However, the cd-key is a different one on the upgrade than the original installation (but is unused). I also was needing to know if it would allow me to change my CD-key (I'm needing a fresh install with my other disk and want to keep both my systems with seperate CD Keys).

Any chance the Hive Mind can help me out on this one?

I believe you can chagne your XP cd-Key at activation time by going the telephone support route and clicking Change Product key. However I think the retail/upgrade version is different than oem and you might be out of luck at that point since it would just give you an invalid product key.  

Well truthfully I only need (as of utmost importance) to change the CD-Key on my current primary system in addition to a fresh install. I just need to know if running the upgrade version of Windows XP Pro would still allow me to install and update my Cd-Key for This specific system.

The upgrade XP CD will allow you to do a clean install if you put in a win 98 CD for it to verify.  
It would, of course, be unethical to download and burn a win 98 CD for this purpose even though you would never install Win 98.

Good luck,

No.  The cd key ranges are different for full installs and upgrades, install 2k or 98 or something then upgrade.  

Ok so Win ME should prolly work as well, XP would prolly allow me to downgrade then right? The whole point of me doing this is to rid myself of the previous install of windows but w/o losing all my registry information, and I know by reinstalling Windows it doesn't overwrite your registry. (At least I think :P)

why not BACK UP your registry and have it added back in after an install?

Do you have a completely new cd key with the upgrade cd?  If so you can just put the cd in and select upgrade then "upgrade" over the original install.  The only problem you may run into is if your current install is a newer version than the cd.  IE its a older cd with service pack 1 and you have already updated to service pack 2

Quoted: Do you have a completely new cd key with the upgrade cd?  If so you can just put the cd in and select upgrade then "upgrade" over the original install.  The only problem you may run into is if your current install is a newer version than the cd.  IE its a older cd with service pack 1 and you have already updated to service pack 2

Well I'm actually receiving it in the mail, so I don't "have" it yet... I've never used an upgrade, I've always used fresh installs. Do they come with one? I just assumed it did.

If the Upgrade "saves" your old CD-Key, that would actually be cool too, I can install ME and do it, but If I can install over my current install with The upgrade (that is assumed to have a fresh CD key) that would be much more convenient. I dont want to have to format basically :( This is the whole point in my questions being asked, I have so much crap on my PC that I've saved throughout the years that it would take too long to backup. I'm trying to do this as cleanly and easily that I possibly can.

If any of you have personal experience with upgrade versions, whether or not they come with a CD Key is another of my questions now :(