Verifying if a DC is a RODC

I'm in a situation where I'm trying to help out a friend who has little knowledge of his system. He is trying to install a program onto his domain controller and it gives an error stating that it cannot be installed on a RODC. This is the only DC that he has so I am assuming it is not a RODC. Is there a specific way I can have him determine what kind of server this was loaded as? I had him send me a dcdiag /v printout, but I couldn't determine one way or another if it was read only or not.

In 'Active Directory Users And Computers' browse to the RODC's computer object the DC Type should contain say ReadOnly if it is a RODC. The computer object properties on tab 'Managed by' should also show what type of DC it is.