FAQ: Microsoft offers cheapest-ever Windows upgrade - Computerworld
Can I upgrade from one of the Windows 8 previews Microsoft has shipped this year? Maybe.
In follow-up answers, Microsoft said that users running Windows 8 Release Preview -- the newer of the two sneak peeks, shipped on May 31 -- can upgrade using the Windows.com upgrade tool and pay the $40.
However, the only bits that are retained during that upgrade are personal data files. Other elements, including the applications, Windows settings and user accounts that migrate from Windows 7, do not.
Windows 8 Release Preview users can upgrade to final edition for $39.99 with prior valid license | The VergeMicrosoft's Windows 8 Pro upgrade offer will also apply to users of the Release Preview edition, the company has revealed. The deal, that lets Windows XP, Windows Vista, and Windows 7 users upgrade to Windows 8 Pro for $39.99, will be offered to Release Preview users once the final version is available. However, a previous valid license of Windows will be required for upgrade eligibility.
Microsoft tells us that if you had a "previous version of Windows that qualified on the PC already and installed Windows 8 Release Preview on top of it, you still qualify for the upgrade," because of the previous installation of Windows. Users who clean install a version of Release Preview "on top" of a previous version of Windows (Xp, Vista, Windows 7) will also be eligible for the upgrade. The software maker cites a method of installing Windows 8 Release Preview on a Mac running OS X as an example of how you would have to pay for a full copy of Windows 8. "You would need to get the System Builder version instead of the upgrade to run on that Mac," says a Microsoft spokesperson.
The cheaper upgrade path is expected to be made available primarily through online downloads when Windows 8 launches later this year. Microsoft is currently preparing final builds of Windows 8, with an expected RTM due later this month and a release to the public tentatively scheduled for mid-October, according to those familiar with the company's plans.
Windows 8 Release Preview users eligible for $40 RTM upgrade, require past license - Neowin
It recently came to light that the upgrade from previous versions of Windows to Windows 8 Pro would cost just $39.99 until January 31, 2013; a surprising bargain considering previous upgrades cost more than $100. With the deal, anyone can upgrade their copy of Windows XP, Vista or 7 to the full version of Windows 8 Pro. A physical upgrade DVD will also be available in retailers for $69.99.
At the time of the announcement it was unclear if you would be able to upgrade from the Release Preview to the Release to Manufacturing (RTM) final version of Windows 8 for this low price, but since then it has been revealed by Mary Jo Foley that this is indeed possible. Speaking on the Windows Weekly podcast, Foley mentions that the $39.99 upgrade deal also applies for those people testing Windows 8.
...[$39.99] is also the price for people who are testing Windows 8... I just asked to make sure and they're saying yes, if you have been testing the Windows 8 Release Preview you can upgrade for the $40 too.This means that you can effectively get a full copy of Windows 8 before January 31, 2013 for $40 by simply downloading and installing the Release Preview for free, and then upgrading to Windows 8 Pro for the low price of $39.99. That said, it is good to see Microsoft is rewarding all those who have spent time testing Windows in the months leading up to the release.
Update: Brandon LeBlanc mentions on the Microsoft blog that to upgrade from the Release Preview you need "an underlying license for either Windows XP, Windows Vista or Windows 7". Luckily for most people, finding a Windows license from the past 11 years shouldn't be that hard, still enabling you to upgrade extremely cheaply.
It should also be noted that those who upgrade from the Release Preview will only be able to keep their documents and files, with previously installed applications not making it through the update process. Thanks for the update, lcg, in the comments.
Actually, thinking back now, Windows 8 was my main OS for literal 24/7 usage for about a year now with the Developer Preview. I was immediately hooked on the Start Screen, never looked back!
I ran it as dual boot, until the RTM. I now have the RTM running as my primary, waiting for the official public release to replace it. I have just made the big decision and deleted my Windows 7 installation.
The DP sucked to the point of unusability, and that's being generous.
It was the CP when things started to come together.
Still running the CP on the other laptop. Geez it looks
good compared to the RTM on this machine....and it
runs as sweet as a kitten...
I may do the same thing in a month or two...
I wish I could use 8 as primary, but unfortunatly I need to run my business on 7 yet. I don't trust 8 totally (stable though) and I need to upgrade my Office 2000 Pro. That runs fine on 7, but can't seem to load it on 8. OS files missing to do so. I don't want to upgrade Office 2013 yet until they get the kinks out and until final release. I did run the preview on 8 for a while until it expired. I liked it and it ran fine. Certainly don't want to buy Office 2010 for that would be a waste of money at this point. The only qualms I have with 8 is the lousy email app and not enough apps yet.
Stuck in the middle for now I guess. "Yes, I'm stuck in the middle with You"................