Fix: Logon Failure, Unknown username or bad password, while joining Shared Computer

If you’re in a workplace where you often need to connect different systems, like in a computer class, exam center, etc., you need to share one system with another one. However, sometimes sharing may not be easy and you may face trouble while connecting machines. If you’re not able to access a shared folder on Windows 8, from a Windows 7 machine, that is a different issue. But if your are unable to join a Shared Computer, then this post may help you troubleshoot the problem.


Consider a scenario – you fixed the sharing for a system to “everyone”. When you go on to enter your network credentials to connect to the shared computer, even when you submit the correct credentials, you receive a message Logon Failure Unknown user name or bad password. When you try to join that system from another machine, you’re kept asking the credentials again and again. When you enter the system username and password, you get a logon failure message. So basically, invalid credentials are causing  the issue, although you have set permission of shared system as ‘without requiring credentials’.

Logon Failure Unknown username or bad password

If you are facing this problem, here is simple method to resolve this issue:

Making mistakes while editing the Windows Registry could affect your system adversely. So be careful while editing registry entries and create a System Restore point before proceeding.

1. Press Windows Key + R combination, type put regedit in Run dialog box and hit Enter to open the Registry Editor.

2. In the left pane of Registry Editor, navigate here:


logon failure unknown username or bad password

3. In the left pane of this registry location, highlight the Lsa key and come to its right pane. Then, right click in blank space and select New -> DWORD Value. Give the newly created DWORD (REG_DWORD) as LmCompatibilityLevel name double click on it to get this:


4. In the above shown Edit DWORD Value box, put the Value data equals to 1. Click OK. You can now close Registry Editor and reboot the machine. After restarting your computer, you’ll be easily able to join the shared system.

Let us know if this worked for you. If it did not, you may reverse the changes or restore your Windows computer back.

Posted by on , in Category Windows with Tags
An Electrical Engineer by profession, Kapil is a Microsoft MVP and a Microsoft Content Creator. Please read the entire post & the comments first & create a system restore point before making any changes to your system.