Hi had an issue today with a WDS Server on Windows Server 2008 R2 SP1. Whenever I went to add a driver package to a boot image the "Add Driver Packages to Boot Image Wizard" would freeze when trying to mount the image and come up with not responding.
When running the wizard again the following error would be received:
Error Occurred while trying to execute this command.
Error Code: 0xc1420127
In which I needed to browse to "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WIMMount\Mounted Images" and delete any keys below this to run the wizard again.
To resolve the problem I ran the following command to Uninitialize the server.
Opening the WDS Console allowed me to run the configuration wizard again. After running the configuration wizard and re-configuring the server I then ran the "Add Driver Packages to Boot Image Wizard" which completed successfully.