Hi,
I've generated a configuration file for install through the GUI. When rerunning setup.exe using this file, there are a few problems which need to be fixed by hand, but the one I've been unable to fix is the INSTANCENAME parameter. It is ignored by the GUI and the default instance is selected in the Instance Configuration panel. Here is the line.
INSTANCENAME="D1"
I'm using a SQL 2008 SP1 merged drop to install.
Setup.exe version is 10.0.2531.23