For those of you using a Windows 7 machine, Microsoft is ending mainstream support for the operating system today.

Don't panic, though. Your computer will still work and receive security updates. Mainstream support mainly refers to free phone and online support, as well as non-security updates, which is offered for five years after the release of an OS or two years after its successor hits the market.

Microsoft won't end security updates for your Windows 7 PC until Jan. 14, 2020. By that time, Microsoft hopes you will have upgraded to a new version of its OS, whether that is Windows 8, 10, or beyond.

But as we saw with Windows XP, it can be difficult to get people to move on. Extended support for Windows XP ended on April 8, 2014. At the time, however, 27.69 percent of global PCs were still running the outdated OS, not to mention a businesses like hospitals and ATMs.

Windows 7 arrived in October 2009 and was heralded by then-CEO Steve Ballmer at a "simpler, faster" operating system. By and large, Windows 7 was well-received and is currently in use on 56.26 percent of global PCs, according to December stats from Net Applications.

Windows 8 has not been as successful, and is only in use on just under 19 percent of PCs, barely eclipsing XP at 13.57 percent. Mainstream support for Windows 8 ends on Jan. 9, 2018, while extended support is set to expire in 2023.

PC Magazine