Microsoft'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.