Even thought millions upon millions of people still use Windows 7 across the world, Microsoft will be ending mainstream support of its most popular OS early next year.
The company normally supports its operating systems for a minimum of 10 years, with a minimum of five years for its 'mainstream' support - or for two years after its successor is released (in this case, Windows 8). Another minimum of five years (or an additional two years after its successor is released) in something Microsoft calls extended support.
During the first few years with mainstream support, Microsoft offers the OS security updates, non-security hot-fixes, performance enhancements, feature improvements and design changes, all for free, as well as still accepting warranty claims. Once this mainstream support has passed, and it is entering extended support, the company only provides security updates, and paid hotfix support.