You can continue to use Windows 7, but once support ends, your PC will become more vulnerable to security risks. Windows will operate but you will stop receiving security and feature updates.
Windows 7 can still be installed and activated after support has ended. However, to avoid security risks and viruses, Microsoft recommends that you consider upgrading to Windows 10.
Support for Internet Explorer on Windows 7 devices will be discontinued on January 14, 2020. As a component of Windows operating system, Internet Explorer follows the same support lifecycle.
Microsoft 365 Business comes with a free upgrade for users with a Windows 7, 8, or 8.1 Pro license on their device. By purchasing Microsoft 365 Business your users can upgrade all of their old Windows Pro licensed devices at no additional cost.