New
#1
Ed Bott confirms Upgrade clean install w/o prior OS
Finally, some answers to Windows 7 upgrade questions
Better late than never. We had these hashed out in the sticky on the first night!
Following Brink's tutorial, I used the Upgrade disk to do a formatted clean install from boot, which activated first time. I wanted to confirm that the installer is reading a previous OS from the boot mode on the disk.
So I zeroed HDD on a laptop and tried to install from boot, but this time the key was rejected and activation was refused after it went online - I had to do the old VIsta "upgrade over upgrade" (repair install) again from the desktop to get it to take the key and activate. *edit: see Paul Thurrot's fix here: http://www.winsupersite.com/win7/cle...rade_media.asp
I think this means that it obviously can't read the prior OS on HDD when zeroed, but can read a previous OS on formatted HDD, probably as it is scanning the drive early on BEFORE formatting.
As far as why the "upgrade over upgrade" works as a last resort, perhaps MS allows the "upgrade over upgrade" to activate just with the presence of a prior OS (the first upgrade) and not prior activation because such a "Repair Install" is also needed to fix the OS. So they liberalize the activation by allowing any working Upgrade key.
Last edited by gregrocker; 27 Oct 2009 at 19:59.