Script Execution Policy
By default, no scripts can be run on a new installations. Not only must you enable script execution, but you must choose if you require scripts to have a digital signature.
In a PowerShell command window, type Get-Help About_Signing to see what is best for your scenario.
If you are satisfied by RemoteSigned, simply type in Set-ExecutionPolicy RemoteSigned in an PowerShell session that is running with elevated privileges (using Run As Administrator).