Exchange 2010 OWA errors in Exchange Management Console

After the installation of Exchange 2010 if you navigate to Server Configuration->Client Access Server.
You may get the following error:
“An IIS Directory entry couldn’t be created. The error message is Access is denied.
.HResult= –2147024891 it was running the command Get-OwaVirtualDirectory”.

This is resolved by adding the Exchange Trusted Subsystem group to the local Administrator group on the Exchange 2007 server.