I ran into this installation error for more then 4 hours ! I tried lots of stuff to make it & searched a lot till I found this article http://www.mattgrovesblog.com/2009/11/sp2010-installation-error.html#axzz1ssEbtjSV
so the exception I was getting was in step 9 is this;
“An exception of type Microsoft.SharePoint.PostSetupConfiguration.PostSetupConfigurationTaskException was thrown. Additional exception information: An error has occurred while validating the configuration settings. An exception of type System.ArgumentNullException was thrown. Additional exception information: The errorData argument cannot be null or zero length.“
After some diagnosis found this was due to the Windows firewall blocking PSConfig from talking to remote hosts!
So, what the error should say is:
Due to the Windows Firewall being enabled the PSConfig cannot create a connection to remote hosts (eg. your SQL server!!). Please allow PSConfig out through the firewall!
Having now created the firewall rule I am making progress!
Of course, some will simply disable Windows Firewall 😉