I'm running into the same problem, but I don't understand the solution: "Due to moodle_user not specified in user mappings (user) as dbo owner."
I'm also using Windows Server 2008, IIS 7, SQL Server 2008, PHP 5.2.14 non-thread with opentds. Database has been created with no errors during Moodle install.
Can someone ellaborate?
Thanks,
Paul