Microsoft started a campaign in which they are actively sending notifications to Windows 7 users and warns them that support for this operating system will end January 14, 2020. Those who still work with the old version are advised to upgrade to Windows 10.
Multiple users have been reporting that they are getting a notification, that started roughly a week or so ago. The notification popup features a ‘Learn more’ button on the right. If you click on the button, it opens Microsoft’s webpage in the browser to detail the end of support deadline and options available to the customers. There is also a box ‘Do not remind me again’, which if clicked, is supposed to stop displaying this notification again.
You could continue to use Windows 7 as it'll obviously not halt working, however, the operating system will stop receiving software and security updates as of 2020 and this will put the system at a greater risk for viruses and malware. Windows 7 was released to the public in 2009.