Knowing which Operating System your computer is running can help tremendously in the troubleshooting process.
Windows has many ways to view your system information. The easiest method is by using the keyboard shortcut to hold the Windows key and press the Pause/Break key. The Windows Key is located on the bottom-left between Ctrl and Alt. The Pause/Break key is located on the top-right of your keyboard. Here are a couple of other ways of finding your Operating System!
Microsoft support has documentation to help determine your operating system. To find out which version of Windows you're using, check out their article:
https://support.microsoft.com/en-us/help/13443/windows-which-operating-system
The newest browser versions and software are built for the latest operating systems. To find out which version of Apple's OS X you're using, check out this support article: