"Neither the manufacturer or installer, nor Microsoft, is obligated to supply earlier versions to you," read the licensing agreement. "You must obtain the earlier version separately."
However, unless Microsoft changes policies, OEMs will be able to offer new Windows 8 Pro PCs that are downgraded to, for example, Windows 7 Professional, at the factory. Computer makers will also be able to continue to sell Windows 7-powered PCs for up to two years after the debut of Windows 8 -- in other words, until late Oct. 2014.
For the latter, customers who later want to upgrade to Windows 8 must pay for the upgrade. That's not the case with a PC purchased with Windows 8 Pro that has been downgraded to Windows 7 Professional (or Vista Business).
"At any time, you may replace an earlier version with Windows 8 Pro," read Microsoft's licensing agreement.
Do-it-yourself downgrades will be more complex with Windows 8, however, as users must first modify the PC's BIOS to boot into what's called "legacy mode." By default, Windows 8 will use UEFI-mode (Unified Extensible Firmware Interface) boot on new PCs to enable some new features, including Secure Boot.
Notebooks, desktops and other devices powered by Windows 8 Pro will go on sale Oct. 26.
Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at @gkeizer, on Google+ or subscribe to Gregg's RSS feed. His email address is firstname.lastname@example.org.
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