[AT and T RealVNC 4]

RealVNC uses innosetup to install. Here is a link to some command-line switch documentation for this installer:

http://unattended.sourceforge.net/InnoSetup_Switches_ExitCodes.html

Link to some documentation about configuration parameters that you can set in the registry:

http://www.realvnc.com/products/enterprise/4.0/winvnc.html#Configuration