I know it is possible to only use the upgrade cd of windows vista to do a clean install. My question is: Will it be registered genuine if I do it this way? (This is a new, never used before key, and a legit one)
If you have trouble activating Windows 7 open the Windows Activation Wizard while in Windows 7 to use the phone and activate Windows:
1. When you reach the desktop click Start, then in the Search box type: slui.exe 4
2. Press Enter on your Keyboard
3. Select your Country.
4. Select the Phone Activation option, then call the number given and hold for a real person.
For more details: http://www.sevenforums.com/tutorials/18715-activate-windows-7-phone.html
Note: Have your Windows XP/Vista 25 character product key available to give to the rep for confirmation of upgrade eligibility.