To set the ExecutionPolicy using Powershell, run Powershell as Administrator.
Type in Set-ExecutionPolicy followed by the ExecutionPolicy you wish to use.

Restricted: Restricted is the default execution policy. PowerShell scripts are not allowed to run.

All Signed: All Signed means thath if they are signed by a trusted publisher.

Remote Signed: Remote Signed means, any PowerShell scripts that have been locally created will be allowed to run.

Unrestricted: As the name implies, Unrestricted removes all restrictions from the execution policy.

Microsoft has disabled scripting by default to prevent malicious code from being executed.