How to Find Out What Kind of Operating System I Have
Many software applications and peripheral devices are developed with a specific operating system in mind and won't work on an unsupported OS. To find out whether a particular application or device will work on your computer, check your system's information to learn which platform you're using.
Press "Windows-C" or swipe in from the top right side of the screen to display the Charms bar. Click or touch "Settings | Change PC Settings | PC Devices | PC Info." Look next to System Type under PC to see whether you're running a 32-bit or 64-bit version of the operating system, and then look next to Edition under Windows to see which edition of the OS is installed on your PC. For Windows 7 and earlier, click "Start," right-click "Computer" and then select "Properties" from the context menu to open the System window. Review the information next to System Type and under Windows Edition to find out your OS.
Mac OS X
From the Apple menu, select "About This Mac." Review the information next to Version to see your version number. Click "Version" to see your build number.