Recently I was doing yet another install of SharePoint 2010 and the pre-requisite installer would keep failing on the IIS/Application server setup. It simple wouldn't run. I looked at the log file and there was nothing apparent in the log file that would tell me what was happeing. Because I have done the install many times, I realized the only piece that wasn't doing anything was the IIS setup. Looking at the command that the prereq installer would execute:
servermanader.cmd -inputpath <path to config>
I decided to run this manually and see what was up. It was here where you do get an error:
Error: A configuration started by SP2010-WFE1Administrator is currently in progress. Before you can start a configuratio, SP2010-WFE1Administrator must log in to complete the current configureation or the configuration in progress must be canceled.
Would have been nice if the SharePoint installer would have bubbled up the exception to the UI.