Its worth mentioning that this method allows any interaction with the user during the Task Sequence... I have used this myself in a upgrade scenario using USMT, and a recovery partitions were causing issues. I added one task to check the partitions on the disk, and ask if the user (IT person) want to delete the recovery partition or not. If the user choose Yes, the partition will be deleted, and a registry key is written to WinPE's registry. The next step is a reboot task with a condition on the registry key. I also choose to run the actual USMT task with with method as well, for to keep an eye on the USMT-output...
