This time I was working on a customer in Jamaica and faced an issue installing updates in a SharePoint 2010 farm, basically we were installing a CU and when we try to start the PsconfigGUI we got an error screen preventing us to update SharePoint properly:
At first sight I though reinstalling the hotfix is an option but I got a message saying, the fix is already installed, so that meant binaries were already there.
Ok a reboot will fix it like in the most cases, but this time didn't work.
Then looking into the KB I found that Installcheck -noInstallcheck psconfig parameters could help, so I ran PowerShell and typed psconfig -cmd installcheck -noinstallcheck.
Magic, this time SharePoint Configuration Wizard started and completed successfully.
Hope this can help you in some way!