How to Install and Update Windows Subsystem for Linux 2 (Premium)

Though this process will be streamlined in the future, installing the Windows Subsystem for Linux (WSL) 2 today requires multiple steps. Here are the steps I’ve used, multiple times, to make sure this goes as efficiently as possible.

Note: These instructions are an excerpt from the Windows 10 Field Guide, which is now being updated for Windows 10 version 2004/20H2. They will be included in a coming update to the book.
Enable hardware virtualization
To get started, you will first ensure that your PC's hardware virtualization features are enabled in its firmware settings. You can access the interface by navigating to Settings (WINKEY + I) > Update & Security > Recovery and then clicking the Restart now button under "Advanced startup." When the Windows Recovery Environment appears---it's a blue screen with the title "Choose an option"---navigate to Troubleshoot > Advanced options > UEFI Firmware Settings > Restart. Your PC will reboot again display its firmware settings interface.

What you see here varies by PC, but you're looking to enable any available options under a "Virtualization" heading.

Note: On the PC I used to take screenshots for the book, I navigated to Security > Virtualization and enabled the only two options, "Intel (R) Virtualization Technology" and "Intel (R) VT-d Feature."

Tip: If you're unsure how to find these or similar options on your PC, consult with your PC maker or use Google search.
Enable optional Windows features
With that done, you can reboot into Windows again. Then, open the Start menu, type feature, and then select "Turn Windows features on or off" from the Start search results. The Windows Features control panel appears.

Scroll down to the bottom of the list and select (enable) the following two features:

Virtual Machine Platform
Windows Subsystem for Linux

Then, click OK and, when prompted, select the Restart now button to reboot your PC so that the new features can be completely installed.

When that's done, it's time to update the Linux kernel used by WSL. In the future, Windows will do so automatically via Windows Update. Temporarily, however, you will probably need to update the kernel manually. To find out whether this is so, open Windows PowerShell (or the Command shell) and type the following command:
wsl --set-default-version 2
If Windows PowerShell responds with "WSL 2 requires an update to its kernel component. For information please visit https://aka.ms/wsl2kernel," then you need to update the kernel manually. So navigate to https://aka.ms/wsl2kernel using Microsoft Edge or another web browser and download the latest WSL Linux kernel package and install it. No reboot is necessary.

Now, when you run the PowerShell command noted above, it will work, and it will simply respond with "For information on key differences with WSL 2 please visit https://aka.ms/wsl2".
Install a Linux distribution
That's good, but you're not done yet. Befo...