An IIS directory entry couldn't be created. The error message is Access is denied.. HResult = -2147024891

Today I did a Exchange 2007 to Exchange 2010 migration. we had to keep one of the Exchange 2007 CAS serveres for the Microsoft Transporter Suite (Lotus Notes integration).

When doing an get-owavirtualdirectory and other cmdlets involving all servers in the organisation, I got the following error message:

The solution for this error messsage is to add the Exchange trusted subsystem to the local admin group on Exchange 2007 servers.