On April 14, Microsoft plans to shift Windows XP from 'mainstream support' to 'extended support.' This will change the availability of free fixes and updates for many people:

Typically, Microsoft keeps a product in the former for five years, then moves it into the latter for another five, for a total of 10 years. However, the long span between the releases of XP and its successor, Windows Vista, forced the company to push out the support deadline to 13 years altogether. Also, two years ago Microsoft bumped support for Windows XP Home and XP Media Center to the 2009 and 2014 dates, matching the dates that had previously been set for Windows XP Professional, the designated business edition of the operating system.

By Microsoft policy, mainstream support delivers free fixes -- for security patches and other bug fixes -- to everyone. During extended support, all users receive all security updates, but non-security hot fixes are provided only to companies that have signed support contracts with Microsoft. Several Microsoft spokespeople confirmed that Tuesday. "Customers will have access to extended support for paid support, security support updates at no additional cost and paid hotfix support," a company spokeswoman said in an e-mail. Firms must purchase an extended support contract within 90 days of XP's mainstream support retirement in April. "All security updates are provided through both mainstream and extended support," added Frank Fellows, another Microsoft spokesman.