Step 1: Press “Windows Key” and “R Key” at the same time as shown above:
You’ll see Run Prompt where you need to type a command dxdiag to open DirectX Diagnostic Tool.
After typing command, press enter and you’ll see DirectX Diagnostic Tool as below. One the Operating System option in System Tab, you’ll See details of Operating System such as Name, Version, Word Length and Build etc. In my case, my OS is of 64 bits.
Hope you got it.