Hi Don,
This problem may occur if the Execution policy is set to Restricted. To troubleshoot it, please try the following steps:
1. Run Windows PowerShell as an administrator. To do this, right-click PowerShell, and then click Run as Administrator.
2. Type the following command, and then press ENTER:
Set-ExecutionPolicy Unrestricted
3. Try to connect Windows PowerShell to the Exchange Online Service again
Here is the detailed information about the error message: http://support.microsoft.com/kb/2411920
Thanks,
Bourne Zhang