Microsoft confirmed that it will sell what it calls "upgrades" for Windows 7 (download) to users running the Windows XP operating system.
"Regarding XP, customers can purchase upgrade media and an upgrade license to move from Windows XP to Windows 7," a company spokeswoman said in an e-mail this morning. "However, they will need to do a clean installation of Windows 7."
In a follow-up reply to questions, the spokeswoman fleshed out what Microsoft means by upgrade. "The 'upgrade' part is referring to the license," she said. "You will be able to get the discounted 'upgrade' license, but it will include full bits."