Windows 7 is an operating system released by Microsoft in 2009. Active development ended in January 2015, so there will be no further service packs, but Windowsmore
Windows 7 is an operating system released by Microsoft in 2009. Active development ended in January 2015, so there will be no further service packs, but Windows 7 security updates will continue to roll out until January 2020. Windows 10 is Microsoft's current OS, and the most recent version is the August 2016 Windows 10 Anniversary Update.
Linux Mint is based on Ubuntu (which itself is descended from Debian), but it removes Ubuntu's ironically divisive Unity interface in favor of a more traditional desktop look. You actually have several to choose from, and you can swap them in and out. Like Ubuntu, Mint is completely free and centralizes all system and app updates into one tool.
Windows 10 is clearly different enough from Windows 8.1 to be considered a new operating system, which hasn't always been the case with Microsoft's version releases. For desktop users, Windows 10 has more in common with Windows 7 than 8. That shared DNA feels like an intentional result of listening to feedback, as Microsoft did when gamers nearly rebelled against the original design of the Xbox One. It just took longer with Windows.
On the flip side, Windows 10 doesn't feel like a must-have upgrade for the average desktop user (if there is such a person). If Windows 7 or 8.1 does everything you need, there's no killer app in Windows 10 that will change the picture for you.
There are many versions of Linux to choose from, but Ubuntu is arguably the most accessible one. You can download it for free and set it up on a USB thumb drive to install into your computer -- or to run directly off the USB drive. It won't run most PC games, or Photoshop, or Microsoft Office. But for the latter two, GIMP and LibreOffice are credible alternatives. One big plus: Linux is virtually virus-free. Another plus: All of your system and app downloads and updates are centralized into one tool (and updates can be done automatically, if you prefer).