As quietly as Microsoft defined the dates it would stop selling Windows 7, over the weekend it revised its end-of-sales deadlines again, saying it had made a mistake.
Last week, Microsoft told customers that it would require computer makers to halt sales of new Windows 7-powered PCs at the end of October 2014. Now, its sales shut-off page shows "To be determined" instead of the future date.
"We have yet to determine the end of sales date for PCs with Windows 7 preinstalled," a Microsoft spokeswoman said in an email reply to questions Tuesday. "The October 30, 2014, date that posted to the Windows Lifecycle page globally last week was done so in error."
The halt date for retail sales -- Oct. 30, 2013 -- was legit, Microsoft said. "We are confirming that the retail software end of sales date for Windows 7 did happen on October 30, 2013," the spokeswoman said.
Microsoft's practice is to stop selling an older operating system in retail one year after the launch of its successor, and halt delivery of the previous Windows edition to OEMs two years after a new version launches. The company shipped Windows 8, Windows 7's replacement, in October 2012.
The October 30, 2014, date fit that policy. If Microsoft later decides on a different OEM end-of-sales trigger, it would be the first departure from the practice defined in 2010 when Microsoft set the retail drop-dead for Windows Vista a year after the launch of Windows 7.
It's possible that Microsoft will still tell OEMs (original equipment manufacturers) to stop selling Windows 7 PCs in just under 11 months, but did not want to publicize the date now. Microsoft did not reply to a follow-up question asking whether the retreat from the Oct. 30, 2014, date meant customers could infer it would be later than that.
"We'll have more details to share about the Windows 7 lifecycle once they become available," the company said today.
Even if it sticks to the plan and halts sales next year, there will be work-arounds for customers.
Windows 8 Pro, the more expensive of the two public editions, includes "downgrade" rights that allow PC owners to legally install an older OS. Those customers must provide their own Windows 7 installation media, however. OEMs and system builders may also use downgrade rights to sell a Windows 8-, Windows 8.1-, or Windows 8.x licensed system, but factory-downgrade it to Windows 7 Professional before it ships.
And enterprises with volume license agreements will not lose access to Windows 7, as they are granted downgrade rights as part of those agreements.
Most analysts believe that Windows 7 will remain the standard Microsoft operating system deployed by companies for years to come.
"There's a good chance that enterprises will stay on Windows 7 as long as possible," said Gartner analyst Michael Silver in an October interview. If his prediction turns out to be accurate, Windows 7 may reprise the stubborn persistence of Windows XP, the 12-year-old OS that Microsoft will retire in April 2014.
With as much trouble as Windows XP has caused Microsoft -- although the firm has spent time and energy urging customers to migrate to a newer operating system, it appears that more than a quarter of the world's personal computers will be running XP when it's officially put out to pasture -- it seems unlikely that Microsoft would significantly push back the stop-sales dates of Windows 7.
Doing just that was one of the causes of Windows XP's longevity: Microsoft did not stop selling XP in retail until June 2008, months after the launch of Vista (and nearly seven years after XP's debut), and the company let some OEMs sell a class of limited-function Windows XP PCs through October 2010.
Microsoft has pledged to support Windows 7 with security and non-security fixes until January 2015, and provide security updates only through mid-January 2020.
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.