A comment for standard users:

To run the script, the suitable execution policy is needed. Standard is usually "restricted", which does not allow to start scripts.

to change it, use this command:

Set-ExecutionPolicy unrestricted

after executing the script set execution policy back to "restricted":

Set-ExecutionPolicy restricted

 

Here you can find more information:
http://technet.microsoft.com/de-de/library/dd347641