Start WSL as root

 The first user after installing is the default account.

Now, to start Ubuntu WSL app and log in as root instead, use the steps below.

First, close the Ubuntu console prompt for the normal user.

When the command Prompt opens, type the commands below to configure Ubuntu WSL app to login as root instead of a normal user account.

Ubuntu:

ubuntu config --default-user root

Ubuntu 20.04:

ubuntu2004 config --default-user root

Ubuntu 18.04:

ubuntu1804 config --default-user root

After running the command above for the respective Ubuntu version, go and start up Ubuntu WSL app and this time the root account should be logged in.

You can see that the root account is logged in.