UDI Wizard Clears the OSDisk variable
If you need to format the OSDisk in a MDT Task sequence BEFORE the UDI Wizard starts then may have seen this problem in the smsts.log
The Deployment will later fail because the step “Apply Operating System Image” will have an incorrect target path: /target %OSDisk%
The variable actually gets cleared, even though the variable is set correctly in Format step. This is because the UDIWizard use the varible OSDTargetDrive
You can fix this by creating a task sequence variable named OSDTargetDrive with the value: %OSDisk%
Place the variable between the format step and the launch of the UDI Wizard.