July 12, 2010, 8:33 PM — Just a day before Microsoft drops support for Windows XP Service Pack 2 (SP2) , the company announced on Monday that people running some versions of Windows 7 can "downgrade" to the aged operating system for up to 10 years.
The move is highly unusual. In the past, Microsoft has terminated downgrade rights -- which let customers replace a newer version of Windows with an older edition without paying for two copies -- within months of introducing a new OS.
While few consumers may want to downgrade from Windows 7 to XP -- unlike when many mutinied against Vista three years ago -- businesses often want to standardize on a single operating system to simplify machine management.
Monday's announcement was the second Windows XP downgrade rights extension. Microsoft originally limited Windows 7-to-Windows XP downgrades to six months after Windows 7's release, but backtracked in June 2009 after an analyst with Gartner Research called the plan a "real mess."
Instead, Microsoft later said it would allow downgrades to Windows XP until 18 months after the October 2009 debut of Windows 7 , or until it released Windows 7 SP1.
In either scenario, XP downgrade rights would have expired sometime in 2011, perhaps as early as April.
On Monday, Microsoft again changed its mind. Users running Windows 7 Professional or Ultimate will now be able to downgrade to Windows XP Professional throughout the entire lifecycle of Windows 7.
"Our business customers have told us that the removing end-user downgrade rights to Windows XP Professional could be confusing," said Microsoft spokesman Brandon LeBlanc, in an entry on the a company blog .
Windows 7 Professional won't be fully retired until January 2020; the Ultimate edition will be put out to pasture five years earlier, in January 2015.