PC users running Windows 7 have been warned to upgrade to avoid possible cyberattacks as support for the software ends.

The 10-year-old operating system will no longer receive critical updates from Tuesday onward, meaning Microsoft will stop patching any weaknesses that appear, making machines vulnerable to hacker attacks.

According to NetMarketShare estimations for the end of 2019, Windows 7 is still one of the most popular Windows operating systems with a 32.7% global share, second only to Microsoft’s most recent version, Windows 10, at 47.7%.

Windows 7-based computers will remain functional but will no longer be secure.

Companies which may not be ready for the move can choose to pay Microsoft for extended security updates through to January 2023, though it is sold on a per-device basis and the price will increase each year, to encourage businesses to upgrade.