The Essential Business Server installation steps for the Management Server might require you to insert the Prerequisite Planning Tools DVD into the Infrastructure Master to run schemaupgradetool.exe. What if you do not have a DVD drive on the current infrastructure master?
Then copy over the network the SCHEMAUPGRADETOOL.EXE, MMSNETWORKINGNATIVE.DLL and the entire ADPREP folder. Then run SCHEMAUPGRADETOOL from the command line on the infrastructure master.
This takes no paramaters to run, and takes a few seconds to start up. Though when I ran it on a Windows Server 2003 SP2 infrastructure master it popped up an empty dialog box with an OK button and nothing else – this though seems to indicate success and the Management Server installation can now continue.