Windows 7 was one of Microsoft’s best-loved computing operating systems and most of us are still using it.
According to NetMarketShare’s September 2018 data, 40.88% are still using Windows 7 – compared to the 37.44% who have moved on to the latest operating system, Windows 10.
But like all operating systems before it, Windows 7 will eventually reach the end of its lifecycle, making an upgrade an absolutely essential task for the safety of your PC.
When does support for Windows 7 end?
Microsoft ended mainstream support for Windows 7 on January 13, 2015, but extended support won’t end until January 14, 2020.
Is Windows 7 still safe to use?
Once an operating system enters extended support, it's still very safe to use. It means that Microsoft will continue to patch any security threats but won't add any new features (as it would do during the 'mainstream support' phase).
Source: https://home.bt.com/tech-gadgets/computing/windows-7/windows-7-support-end-11364081315419