Support for Windows 7 and Server 2008 will end on 14 January 2020.
According to Microsoft, "[a]ll good things must come to an end, even Windows 7. After January 14, 2020, Microsoft will no longer provide security updates or support for PCs running Windows 7. But you can keep the good times rolling by moving to Windows 10."
What this means is that your operating system could have unresolved security vulnerabilities that will not be addressed after MS ceases to support these OS's. Yes, using a good malware suite (antivirus + firewall) will help, but they work best when the vendor (MS) is able to provide OS-specific security patches.
Obviously, MS wants you to upgrade to Win10, but that's a decision you have to make. I've been using it at home and work since it was released and I really like it. I still like Win7, but I prefer Win10 ... for the most part. I know people that are so accustomed to Win7 that they really don't want to make the leap. Win10 is enough like Win7 that the move may be fairly easy for more people; but, it's enough like Win8 that it'll have other people wanting to throw their computer out the window.
If you decide to get Win10, you can purchase and download it here on the "Get Windows 10" site. The free upgrade offer ended 29 July 2016. Win10 Home now costs $139.00, while Win10 Pro costs $199.99. Win10 Home is adequate for the average home / student user. Win10 Pro contains additional tools that are more suited to a corporate IT environment. Click here to Compare Windows 10 editions.
One caveat is that, if you have a personal computer running Win10 that you take it to work, you may need Win10 Pro to connect to the Wi-Fi network. If your employer uses WPA or WPA2 encryption on their wireless networks, you most likely won't be able to connect with Win10 Home.
You can find more information here: Upgrade to Windows 10: FAQ.
As always, I'm open to questions and constructive comments. Your feedback is welcome.