Problem:

When the Powershell script is run on the local computer, to add the P: mapped drive and credentials, it all completes correctly but the mapped drive may not be visible in Explorer, to the end-user.

Diagnose:

It's likely that the Powershell script was run in Administrator mode, not in the User context.

Open the command prompt as Administrator and change to the mapped drive.  If it appears when using the elevated Administrator prompt only then the following will fix the problem.

Solution:

Option 1.

Re-run the powershell script but do not elevate it to Run As Administrator.

Option 2.

1. 1. In Registry Editor, locate and then click the following registry subkey:
      HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System
   2. Right-click Configuration, select New, and then select DWORD (32-bit) Value.
   3. Name the new registry entry as EnableLinkedConnections.
   4. Double-click the EnableLinkedConnections registry entry.
   5. In the Edit DWORD Value dialog box, type 1 in the Value data field, and then select OK.
   6. Exit Registry Editor, and then restart the computer