To find which version of Windows is installed on a computer, there are several simple methods:

1. Press the Windows key + R on the keyboard to open the Run dialog box. Type "winver" and press Enter. This opens a window displaying the Windows version and build number.
2. Click the Start button, then go to Settings > System > About. Scroll down to "Windows specifications" to see the Edition, Version, and OS Build info.
3. Another approach is opening the Command Prompt or PowerShell and typing the command "systeminfo", which lists detailed system information including the OS version.

These steps work for both Windows 10 and Windows 11 systems and provide clear details about the specific Windows version installed on the device.