Checking your Windows version using CMD If you are familiar with the Windows Command Prompt, you can quickly and easily find out what operating system version you have using the system info command line utility as follows: 1. Press [Windows] key + [R] to open the “Run” dialog box. 2. Enter cmd and click [OK] to open Windows Command Prompt. 3. Type systeminfo in the command line and hit [Enter] to execute the command. Once the command has been executed, you will be able to see all of the details of your system in the terminal output. This includes the operating system name, version number and build number.