You can now install everything you need to run Windows Subsystem for Linux (WSL) by entering this command in PowerShell or Windows Command Prompt and then restarting your machine.
If you're running an older build, or just prefer not to use the install command and would like step-by-step directions, see WSL manual installation steps for older versions. You can update to the latest Windows version in the Settings menu or using the Windows Update Assistant. To check your Windows version and build number, select Windows logo key + R, type winver, select OK.