I mostly agree, though the "old" version is not necessarily equal to the installed version BEING upgraded.
i.e.
1) in closet = XP home.
2) on PC = Vista Business retail.
3) Want to run = Vista Ultimate Upgrade
I could "upgrade" either (1) or (2) with (3) in terms of licensing requirements, my choice, NOT Microsoft's.
In terms of functional upgrade ACTION, clearly I'd ACTUALLY upgrade FROM what I'm running at the MOMENT, (2) to what I intend to run (3). This is wholly unrelated to the fact that *for licensing purposes* I may consider that I want to upgrade from (1) to (2), and thus when I install (3) it BETTER NOT invalidate the activated license of (2) since I'm fully within my rights to sell (2) or use it on another PC or whatever.
Other scenarios are of course possible. Either way, it better not auto-replace/invalidate your old license.
Not to mention the fact that it's still your right as a consumer to NOT use a product and not lose one's preexisting goods simply for having PREVIOUSLY used something else for a time. So if I Upgrade from XP to Vista Upgrade I can't use XP on a different PC while I run Vista. If, later, I find that Vista has horrible support for some piece of my hardware / software / whatever, I'm certainly within my rights to discontinue using Vista Upgrade and switch back to XP (which it upgraded 'from') since at such a time no use of any Upgrade at all is in place and I'm not bound by its EULA. If at some future date compatibility of Vista with my system / needs improves, of course, I'd be entitled to give the Upgrade another try.
Originally posted by: RebateMonger
As far as licensing, any Windows UPGRADE software requires that the "old" version's license stay with the upgraded computer. For instance, if you've used Upgrade versions of Windows to go from 3.1 to Windows 95 to 98 to XP to Vista Business to Vista Ultimate, then all those previous licenses should remain with your current computer.
There are three types of Windows software: OEM, Upgrade Retail, and Full Retail. Their order of cost is normally: OEM<Upgrade Retail<Full Retail
OEM - Full versions intended for PCs with no operating system installed. The OEM EULA says you can't move the OS license to a different PC
Upgrade Retail - Requires a valid license for a previous version of Windows. The previous version license remains associated with the upgraded PC and should not be used on another PC. The license can be MOVED to another PC.
Full Retail - Full version license that is stand-alone and can be MOVED to another PC.