+```pwsh
+wsl --set-version Ubuntu-20.04 1
+# or
+wsl --set-version Ubuntu-20.04 2
+```
+
+Or by setting the global default:
+
+```pwsh
+wsl --set-default-version 1
+# or
+wsl --set-default-version 2
+```
+
+Note that you _cannot_ set the mode before rebooting.
+
+See also <https://docs.microsoft.com/en-us/windows/wsl/wsl2-index>.
+
+### How to Install WSL with PowerShell
+
+1. Install WSL 1 + parts of WSL 2
+
+ ```pwsh
+ # Install WSL 1
+ dism.exe /online /enable-feature /featurename:Microsoft-Windows-Subsystem-Linux /all /norestart
+
+ # Install VirtualMachinePlatform for WSL 2
+ dism.exe /online /enable-feature /featurename:VirtualMachinePlatform /all /norestart
+ ```
+
+2. Install Ubuntu Linux
+
+ ```pwsh
+ # Install Ubunut Linux
+ curl.exe -L -o Ubuntu_2004_x64.appx https://aka.ms/wslubuntu2004
+ powershell Add-AppxPackage Ubuntu_2004_x64.appx
+ ```
+
+3. Reboot
+
+4. Finish installing WSL 2 (copying the `kernel` twice for good measure)
+
+ ```pwsh
+ # Download and Install the WSL 2 Update (contains Microsoft Linux kernel)
+ & curl.exe -f -o wsl_update_x64.msi "https://wslstorestorage.blob.core.windows.net/wslblob/wsl_update_x64.msi"
+ powershell -Command "Start-Process msiexec -Wait -ArgumentList '/a ""wsl_update_x64.msi"" /quiet /qn TARGETDIR=""C:\Temp""'"
+ Copy-Item -Path "$env:TEMP\System32\lxss" -Destination "C:\System32" -Recurse
+
+ # Also install the WSL 2 update with a normal full install
+ powershell -Command "Start-Process msiexec -Wait -ArgumentList '/i','wsl_update_x64.msi','/quiet','/qn'"
+ ```
+
+5. Then click Ubuntu Linux in the start menu.
+
+See also:
+
+- <https://github.com/microsoft/WSL/issues/5014#issuecomment-692432322>
+- <https://docs.microsoft.com/en-us/windows/wsl/install-manual>.
+
+### Errors: Feature Not Installed & Nested VMs
+
+The most likely problem is that you're on a computer that does not support WSL 2
+(or the necessary VT-x options have been disabled).
+
+The simplest workaround is to switch back to WSL 1:
+
+```pwsh
+wsl --set-default-version 1
+wsl --set-version Ubuntu-20.04 1
+```
+
+See also <https://webinstall.dev/wsl2> (errors section).
+