Microsoft is scrapping security fixes for older versions of Internet Explorer (IE), leaving support only for IE 11. For those not rushing to Windows 10 and its new browser Edge, Microsoft is putting out a final warning for upgrading Explorer.

Microsoft first issued its warning in October to Internet Explorer users that from January 12, only IE 11 will be supported with security fixes and older versions of IE will no longer receive updates. For those who choose to use an older version of Internet Explorer past the end-of-support date, you will be vulnerable to new exploits from there on.

Here is the notice: “Beginning January 12, 2016, only the most current version of Internet Explorer available for a supported operating system will receive technical supports [sic] and security updates. Internet Explorer 11 is the last version of Internet Explorer, and will continue to receive security updates, compatibility fixes, and technical support on Windows 7, Windows 8.1, and Windows 10.”

In terms of assisted support options, both free and paid-for will no longer be supported.

Internet Explorer is still the second most popular browser, with over 15% of global web activity last month. This makes it a target for hackers, who have been known to sit on unknown vulnerabilities, holding them back only to unleash them when there will be no Microsoft reaction.

For those who don’t use IE as their main browser, should still upgrade. If it’s installed on your computer and the computer is connected to Internet, an outdated IE can still be exploited. You can either upgrade, or if you really do not want to, instead remove it from your computer. You can always download again from the Microsoft store if needed.

For businesses worried about running legacy web apps, Internet Explorer 11 does have an Enterprise Mode which offers backwards compatibility and is fully supported by Microsoft.