Windows 7: Clean Win7 Install over Ubuntu?

I had WinXP on an older drive, then I upgraded to Vista 64bit, then the disk crashed. Got a new hard drive and installed just Ubuntu 11.04 on it. Then I missed Windows and decided to get a Windows 7 Upgrade. I thought that since I had the XP product key/sticker (on my Thinkpad T400) AND my Vista 64bit Upgrade (with product key) AND my new Windows 7, I'd be set and legal.

First, the Windows 7 upgrade DVD didn't like seeing the Ubuntu partition and didn't want to install. I popped out the drive, put it in a external caddy and had my other XP machine format it as NTFS. Good. Reinstalled HD and put in the Windows 7 64b DVD and installed Windows 7. Everything went fine untill the Product Key . . . which it would not accept! This is a legit copy I just bought at WalMart, but it wouldn't accept the key! I finally clicked on "Skip" . . . and it went on installing, upgrading and appears to be working fine! What gives? It didn't ask me for my old Vista copy or key, it simply went on and seems to be working fine. I'm using it right now. (Having trouble getting it to see my external monitor, but that's another thread. . .)

If you want to know if your Windows 7 is activated go to Computer> Properties and scroll down untill you see 'Windows activated' or 'Enter product key'

If you install Upgrade version to a new or cleaned HD it will not see an OS and allow use of Product Key up front during install. Instead leave the key blank, then after install do the quick registry edit given here: Clean Install with a Upgrade Windows 7 Version

You may need to wipe the HD of Ubuntu code to install: SSD - HDD Optimize for Windows Reinstallatio.
A simple format - which can be done by the booted installer during install - may not be enough.

Illustrated steps here: Clean Install Windows 7

Just tried that GianniDPC, and it says ". . . only for upgrades and not for clean installs. . ." So, how do I proceed? I don't have the original XP, only the Vista (upgrade I believe) and the Win 7 upgrade.

. . . oh okay gregrocker, will try. Thanks!

Did you do a clean install with the upgrade disk ?

Will try Gregrocker's suggestion. Thanks again!

Be sure to do step one in the tutorial:
SSD / HDD : Optimize for Windows Reinstallation

You need a full version disc to upgrade from. Two upgrade discs won't do it.

If XP came with or was installed on the machine then it qualifies to use Windows 7 Upgrade version.

Just reread the first post. Poster does have the sticker with the serial number. Didn't see that. Or more to the point, read it but didn't click.