With Microsoft having already announced its decision to pull the plug on its Windows XP operating system, Microsoft and third-party countdown clocks recently showed that the XP has less than 500 days of life left.

The official XP retirement countdown clock - which runs only on Windows 7 - offered by Microsoft, as well as some third-part countdown clocks, flipped to 499 days on Saturday; thereby indicating that XP has fewer than 17 months to live.

The last and final security update for Windows XP will be issued by Microsoft on April 8, 2014; after which the software giant will discontinue its support for its 11-year-old OS.

With Microsoft to have ultimately maintained the Windows XP OS for 12 years and five months before discontinuing support for it in April 2014, Web metrics firm Net Applications has revealed that as many as 40.7 percent of the desktops and notebooks which went online last month were powered by XP.

Despite the fact that Microsoft has been fervently urging the XP users to upgrade at the earliest possible because of the imminent April 2014 exit of the OS, analysts believe that XP will continue to be used by millions of users even after the 2014 deadline.

Towards that end, Gartner analyst Michael Silver said that "there's a good chance" that 10-15 percent of enterprise PCs will continue to be powered by Windows XP even after April
2014.