Check this article before purchasing:
An Ultimate step-by-step guide on how to purchase and activate a Windows 7 Extended Security Updates 2020 and 2021 on your computers

Support for Windows 7 is ended

After 10+ years, support for Windows 7 is ended on January 14, 2020. We know change can be difficult, so we are here to help you with recommendations for what to do next and to answer questions about end of support.

What does end of support mean?

When Windows 7 reaches the end of support on January 14, 2020, your computer will still function but Microsoft will no longer provide the following:

• Technical support for any issues
• Software updates
• Security updates or fixes

While you could continue to use your PC running Windows 7, without continued software and security updates, it will be at greater risk for viruses and malware. Going forward, the best way for you to stay secure is upgrading to Windows 10. And the best way to experience Windows 10 is on a new PC. While it is possible to install Windows 10 on your older device, it is not recommended.