Sfdwhf

I have installed Linux Bash on Windows 10 (available from Microsoft), but I've forgotten my password.

I've searched for a solution but I only find suggestions that involve doing something before the system boots, like accessing recovery mode, but that will not work in this case as this Ubuntu is just an application within a Windows system and doesn't have its own boot process.

How can I reset my password?

• Run bash and make a note of your Linux username (this need not match your Windows username), see How can I find out my user name?
  


• Close Bash on Ubuntu if it is running (or the next command will fail).


• 
  

  In Windows admin command prompt (Super+X, A) change the default user to root:

  
  
  

  ubuntu config --default-user root
  
  

  
  

If you are using Ubuntu 18.04 in WSL, the command has changed to ubuntu1804 , so

ubuntu1804 config --default-user root

• Now Bash on Ubuntu on Windows logs you in as root without asking password


• 
  

  Use passwd command in Bash to change the user password (the user whose password you want to reset):

  
  
  

  passwd your_username
  
  

  
  


• 
  

  Change the default user back to your normal user in Windows command prompt

  
  
  

  ubuntu config --default-user  your_username
  
  

  
  

If you are using Ubuntu 18.04 in WSL, the command has changed to ubuntu1804 , so

ubuntu1804 config --default-user your_username

Watch Full Video to Recover your password Windows Subsystem Linux
https://youtu.be/dTR232yvDCE

Note 1: The subsystem used in the video is not Ubuntu, but Kali Linux. Hence the difference in the command.

Note 2: If you are still using the original Ubuntu subsystem that came with the Anniversary Update, use the command lxrun. Upgrade to the subsystem version distributed via Microsoft Store is recommended.)

The above did not work. Even after changing default user, Bash always opened with my user.

So instead I did this, which worked:

1. 
   

   Edit this file (in notepad or notepad++):

   
   
   

   %localappdata%lxssrootfsetcshadow
   
   

   
   


2. 
   

   Find your normal user, for example:

   
   
   

   user1:$jsdjksadgfhsdf.saflsdf.sadf.safd:17299:0:99999:7:::
   
   

   
   
   

   and simply remove the hash part (below part)

   
   
   

   $jsdjksadgfhsdf.saflsdf.sadf.safd
   
   

   
   
   

   you will see a different hash - I hope :) so it should look like:

   
   
   

   user1::17299:0:99999:7:::
   
   

   
   



3. Save the file



4. 
   

   Start Bash again with root privileges and set your password

   
   
   

    sudo bash
   
    passwd <your-user-name> 
   
   

   
   
   

   You can now set a new password without having to enter the previous one.

   
   

To add to Tmu's answer, here's a Powershell script (gist) that automates the process (including automatically detecting the current default username)

# Resets the password for the default LXSS / WSL bash user

$lxssUsername = (Get-ItemProperty HKCU:SOFTWAREMicrosoftWindowsCurrentVersionLxss).DefaultUsername

lxrun /setdefaultuser root

bash -c "passwd $lxssUsername"

lxrun /setdefaultuser $lxssUsername

For those of you who lost the root password, what worked for me, was updating to Ubuntu 18.04 LTS via the Windows Store. Note, the windows store has two distinct options:

1. Ubuntu


2. Ubuntu 18.04 LTS (Pick this one)

To check your current version, run the following as any user:

cat /etc-*release

You should see a line in the output that says:

DISTRIB_RELEASE=16.01

If you see that, then definitely update to 18.04, and it will prompt you to create new UNIX credentials.