Docker WSL 2 installation is incomplete

There's two ways you can get it to work

1. Using WSL 2 based engine.
2. Without using WSL 2 based engine.

1 - Using WSL 2 based engine

In this page under "Download the Linux kernel update package".

and then Docker will start just fine

2 - Without using WSL 2 based engine

If the goal is just to get Docker running, one can simply start by unchecking the box that says "Use the WSL 2 based engine". This can give the following error

Required Windows feature(s) not enabled: Hyper-V.

Switch to WSL 2 based engine?

To enable Hyper-V: https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/quick-start/enable-hyper-v

So, in PowerShell 7 run the command

Enable-WindowsOptionalFeature -Online -FeatureName Microsoft-Hyper-V -All

which requires to Restart the computer to complete the operation. Then, once starting Docker again, you can get the following error

Docker failed to initialize

One or more errors occurred.

Eventually, just by clicking to start again, Docker will start running