When installing Exchange Server 2007 roles there is different default behavior between the GUI and the command line that you should be aware of. Take a look at this screenshot.
In GUI mode when selecting any server role the Management Tools are selected by default. However, if I were to install the Client Access Role using the command line…
setup /m:install /r:c
…only the Client Access Role would be installed and not the Management Tools. To install the Management Tools as well I would use this command line…
setup /m:install /r:c,t
There is a benefit to this behavior in that it is not always necessary or desirable to install the Management Tools on every single Exchange server in a larger environment. However in most cases for ease of administration having the Management Tools installed everywhere can be a good thing. As long as you are aware of this behavior when planning command line or unattended installations you won’t get caught out.
Link: How to Install Exchange 2007 in Unattended Mode