How to set security setting for Powershell?

When I try to set security for Powershell on Window 7 Home, referring to following linked image, I get following error message

Does anyone have any suggestions on what wrong it is?

Thanks in advance for any suggestions

Setp to set Security for Powershell:

open Powershell, and change directory to the scripts folder. (cd \scripts)

Then, run the following command:

Set-Executionpolicy unrestricted<Enter>

Thanks in advance for any suggestions