In 1000 days, ageing stalwart Windows XP will be thrown to the wolves and cut off from security upgrades.
The software giant would stop supplying security patches and hotfixes for all versions of 11-year-old operating system on 8 April, 2014.
But XP still dominates the Windows portfolio. Gartner says 51 percent of the world's PCs run on the operating system, dwarfing Windows 7 which is installed on 27 percent of machines, according to June figures from NetApplications.
Patches are still being issued to fix critical and high importance vulnerabilities for XP, a service that will end come April 2014.
Not surprisingly Microsoft is encouraging users to upgrade to a newer OS, namely Windows 7, which chief executive Steve Ballmer yesterday touted as the on-ramp to its multi-device successor, Windows 8 due next year.
Despite continue take-up of Windows 7, however, Gartner analysts last year warned that most organisations running XP would not make the April 2014 deadline, predicting a rush to gain Windows 7 skills.
The deadine day would mark an unusually long support period for a Microsoft operating system, lengthened by companies hesitating to upgrade away from XP. Many have only now begun migrations to Windows 7, refusing over past years to switch to Windows Vista.
"Windows XP had an amazing run and millions of PC users are grateful for it. But it’s time to move on," Microsoft's senior community manager for Windows, Stephen Rose, wrote Monday.
"Bottom line, PC's [sic] running Windows XP will be vulnerable to security threats."
Microsoft first announced last year that it would end support for the operating system by 2014, coinciding with a move to wind down supply of machines pre-installed with XP.
To ease transition, Microsoft had already flagged that those companies upgrading to Windows 7 would be able to downgrade to XP any time until 2020.