Allow local scripts

PowerShell's execution policy controls which scripts can be executed (are 'trusted'). The default execution policy is Restricted, meaning that scripts cannot be run at all (although cmdlets can be run interactively from the PS prompt) – when you try to run a script, you get a message like:

Import-Module : File <scriptpath> cannot be loaded because running scripts is 
disabled on this system.

To determine the current execution policy, use:

Get-ExecutionPolicy

To change the execution policy, use:

Set-ExecutionPolicy -ExecutionPolicy NewPolicy

It is good practice only to run scripts signed by a trusted publisher – by specifying policy AllSigned – but this can be inconvenient during development (because every script revision must be re-signed before it can be tested). To allow locally-developed, unsigned scripts to run, use:

Set-ExecutionPolicy -ExecutionPolicy RemoteSigned