How to Reset Linux Bash Shell Password in Windows 10

1. Open Command Prompt

Method 1: Just type cmd in Cortana search box on the taskbar, and you can then click "Command Prompt" from the result.

Method 2: Run Window + R and type cmd, then click OK button to open the Command Prompt.

2. Set "root" as the default user for Linux Bash shell

ubuntu config --default-user root

If you’re running Windows 10 Creators update or earlier, you can change the default Bash user to “root” by running this command:

lxrun /setdefaultuser root

3. Set up a new password for any UNIX user account

Open the Linux Bash shell, it will log you as root without asking a password. You can use the passwd command to set up a new password:

passwd user_name

4. Reset your default user back to your normal Linux account.

Type this in the Command Prompt:

ubuntu config --default-user user_name

or execute this command:

lxrun.exe /setdefaultuser user_name

That's it!