CategoryInfo : NotSpecified: (:) [], PSSecurityException + FullyQualifiedErrorId : RuntimeException

When I try to execute my PowerShell script I get this error:

File C:\Common\Scripts\hello.ps1 cannot be loaded because the execution of scripts is disabled on this system. Please see "get-help about_signing" for more details.
At line:1 char:13
+ .\hello.ps1 <<<<
+ CategoryInfo : NotSpecified: (:) [], PSSecurityException
+ FullyQualifiedErrorId : RuntimeException

You should type the following to make it go to unrestricted mode:

Set-ExecutionPolicy unrestricted

Note:

The Default Execution Policy is set to restricted, you can see it by typing:

Get-ExecutionPolicy