Why This Happens

• Custom URI Misconfigurations: The endpoint or connection URI (Uniform Resource Identifier) passed to the command has a syntax error or an unsupported scheme.
• Corrupted WinRM Configurations: The local or remote WinRM listener configuration has become corrupted or misaligned.
• WS-Management Protocol Mismatches: The client is trying to use a remote shell type or custom plug-in configuration that is not registered or enabled on the target server.
• Corrupted System Files: Underlying Windows management files or dependencies are damaged.

Step-by-Step Fixes

Follow these solutions in order. Test your connection after completing each step to see if the issue is resolved.

Step 1: Run the WinRM Quick Configuration

This utility resets the default WinRM settings, enables the listener, and creates the required firewall exceptions.

1. Click the Start menu, type cmd, right-click Command Prompt, and select Run as administrator.
2. Type the following command and press Enter:

   winrm quickconfig

3. If prompted to make changes and enable the service, type y and press Enter.
4. Type the following command to check if the listener is running properly:

   winrm e winrm/config/listener

Step 2: Verify and Reset the Connection URI

If you are running a specific PowerShell script or command (like Enter-PSSession or New-PSSession), the custom URI parameter may be incorrect.

1. Ensure you are not manually passing an invalid -ConnectionURI parameter. A standard WinRM URI looks like this:

   http://<ComputerName>:5985/wsman

2. If you are using a custom shell, verify that the URI string strictly adheres to the schema required by your target application.
3. Try connecting using the standard -ComputerName parameter instead of the custom URI parameter to see if the default shell works:

   Enter-PSSession -ComputerName Target Computer Name

Step 3: Add the Target Host to the TrustedHosts List

The client machine will reject connections to untrusted endpoints unless they are explicitly added to the local configuration.

1. Open PowerShell as an Administrator.
2. Run this command to view your current trusted hosts:

   Get-Item WSMan:\localhost\Client\TrustedHosts

3. To trust a specific computer, run:

   Set-Item WSMan:\localhost\Client\TrustedHosts -Value "Target Computer Name" -Force

   (Note: You can use `` as the value to trust all computers, though this is only recommended for isolated testing environments).*

4. Restart the WinRM service to apply the changes:

   Restart-Service WinRM

Step 4: Repair Corrupted WinRM Plug-ins and Shells

If a custom remote shell registration is corrupted, resetting the shell infrastructure can resolve the issue.

1. Open Command Prompt as an Administrator.
2. Run this command to restore default WinRM configurations:

   winrm reset

3. Next, check the registered shells on your system by running:

   winrm e winrm/config/Shell

4. Ensure that the default shell URI (http://microsoft.com) is active and has not been overwritten by a broken custom plugin.

Step 5: Run System File Checker (SFC)

If internal Windows components responsible for processing WS-Management requests are corrupted, the SFC tool will repair them.

1. Open Command Prompt as an Administrator.
2. Type the following command and press Enter:

   sfc /scannow

3. Wait for the scan to reach 100% completion.
4. Restart your computer and try the WinRM connection again.