npm: File C:\ProgramFiles\nodejs\npm.ps1 cannot be loaded because running scripts is disabled on this system.

 

The error you're encountering occurs because PowerShell on your system has a restricted execution policy that prevents the execution of scripts like npm.ps1. This is a security measure to prevent the running of potentially harmful scripts, but it can be changed to allow the execution of scripts for legitimate use cases like running npm commands.

To fix this, you can adjust the execution policy in PowerShell. Follow the steps below:

Solution:

1. Open PowerShell as Administrator:

   • Press Windows Key, search for PowerShell, right-click on Windows PowerShell, and choose Run as Administrator.

2. Check the current execution policy: In the PowerShell window, type the following command to see the current execution policy:

   Get-ExecutionPolicy
   

3. Change the execution policy: If the output shows something like Restricted or AllSigned, you can change the policy to RemoteSigned, which allows local scripts to run, and only remote scripts that are signed by a trusted publisher will be allowed.

   Run the following command to change the policy:

   Set-ExecutionPolicy RemoteSigned
   

4. Confirm the change: After running the above command, you may be prompted to confirm the change. Type Y and hit Enter.

5. Close and reopen PowerShell: After adjusting the execution policy, close the current PowerShell window and reopen it (this time, it doesn't need to be in Administrator mode).

6. Run the npm command again: Now you can try running your npm run dev command again, and it should work without the execution policy error.

Explanation:

• Restricted: No scripts can be run.
• AllSigned: Only scripts that are signed by a trusted publisher can be run.
• RemoteSigned: Requires that scripts downloaded from the internet are signed by a trusted publisher, but local scripts (scripts you write or scripts that come with software like Node.js) are allowed to run.
• Unrestricted: No restrictions on running scripts (not recommended unless you trust everything on your system).

Additional Tip:

If you want to only allow the execution of scripts for a specific session (without changing your global policy), you can run this command:

Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope Process

This will apply the policy only to the current PowerShell session.