VMWare shared folder inaccessible with Administrator account
So, as said in the comments, typing net use Z: "\\vmware-host\Shared Folders" in an Administrator command prompt solved the problem.
Create a scheduled task that has the following as an action:
%windir%\system32\cmd.exe /k start /min net use Z: "\\vmware-host\Shared Folders"
Now you should be able to access the folder.