Microsoft has kicked off what it calls a “two-year countdown” to the death of Windows XP and the Office 2003 productivity suite.

Separately, Microsoft announced that Windows Vista, the problem-plagued operating system that never really took hold among customers, exited mainstream support on April 10. In a product’s extended support phase, Microsoft provides security patches to registered users but offers other fixes, including reliability and stability updates, only to organizations that have support contracts with the company.

Windows XP and Office 2003 will no longer be supported as of April 8, 2014, a company spokeswoman said in a recent blog post. On that date, Microsoft will stop shipping security updates for both products.

At that point, XP will have become Microsoft’s longest-lived operating system. The company will have maintained the software for 12 years and five months — or about two and a half years longer than it usually supports an OS. It supported the previous record-holder, Windows NT, for 11 years and five months.

Both XP and Office 2003 have been hugely successful. XP went on sale in October 2001, and Office 2003 launched in October 2003. “Windows XP and Office 2003 were great software releases, but the technology environment has shifted,” said Stella Chernyak, a Microsoft marketing director.

Some customers will continue to run XP even after it is retired. About 16 per cent of organizations “say they will have more than five per cent of their users still on XP even after support ends,” according to Gartner analyst Michael Silver, citing a survey his firm conducted in October 2011.

Not surprisingly, Microsoft wants users to upgrade to Windows 7 now. “If your organization has not started the migration to a modern PC, you are late,” the company said, referring to data that indicates that enterprise OS migrations take 18 to 32 months.