ng : File C:\Users\sigar\AppData\Roaming\npm\ng.ps1 cannot be loaded because running scripts is disabled on this system. For more information, see about_Execution_Policies at code example
Example: File C:\Users\Tariqul\AppData\Roaming\npm\ng.ps1 cannot be loaded because running scripts is disabled on this system.
Set-ExecutionPolicy -ExecutionPolicy Unrestricted