As of tomorrow only Internet Explorer 11 and Edge will be the only browser versions of Microsoft receiving further security updates. If you’re still running a previous version IE, an urgent upgrade is pending…
From the Microsoft Support Lifecycle page:
Beginning January 12, 2016, only the most current version of Internet Explorer available for a supported operating system will receive technical support and security updates. Please visit the Internet Explorer Support Lifecycle Policy FAQ here http://support.microsoft.com/gp/Microsoft-Internet-Explorer for list of supported operating systems and browser combinations.
If your browser is still on an old version because of a compatibility issue, IE11 has Enterprise mode build into it to enable you and your organization to enable backward compatibility (https://technet.microsoft.com/en-us/library/dn640687.aspx)
Also Windows 8.0 runs out of updates, Microsoft asks 8.0 users to upgrade to 8.1
From the Microsoft Support Lifecycle page:
Customers have 24 months to move to Windows 8.1 after General Availability in order to remain supported. See the Windows 8.1 FAQ for more information.
After today, those on Windows 8 will have to upgrade to either Windows 8.1 or Windows 10 to continue getting security updates from Microsoft.