Microsoft has extended the mainstream support period for Office 2007 by six months to align the suite's lifecycle with a little-known provision in the company's support policy. ComputerWorld reports.

Although it's unclear when Microsoft added the six months to Office 2007's lifetime, at one point the software was to leave mainstream support this week, and be put out to pasture in April 2017, the same month that Windows Vista is to retire.

Office 2007 will now exit mainstream support in October 2012, and fall off the support list for good in October 2017.

During the five years of a product's mainstream support phrase Microsoft issues security updates and free fixes for other problems, such as stability and reliability flaws, as well as major upgrades, called "service packs."

In extended support - also five years - Microsoft continues to provide security patches but offers other fixes only to organizations that have signed support contracts with the company.

By its January 2007 on-sale date, Office 2007's original April 2012 and April 2017 milestones fit the usual five- and ten-year spans. But Microsoft's lifecycle policy has a provision that can in some instances supersede the norm.

"Mainstream support ... will be provided for 5 years or for 2 years after the successor product (N+1) is released, whichever is longer," Microsoft's support lifecycle FAQ states.

Because Office 2010, the "successor product" to Office 2007, went on sale mid-June 2010, Microsoft pushed out the end of mainstream support to October to meet the two-year minimum requirement.

Office 2007's third and final service pack was released in October 2011.

Its precursor, Office 2003, will be retired from all support in April 2014, the same month that Microsoft will finally put Windows XP to rest.