Insert a UFD into the computer.
In the Deployment Tools Command Prompt window, type diskpart, and then press ENTER.
Perform the following tasks to prepare the UFD to start the reference computer:
1. Type list disk, and then press ENTER.
2. From the list of disks, identify the number of the UFD. It is important that you identify the correct disk, as you will be formatting the disk. Make sure the size and free space match what you expect for the UFD.
3. Type select disk number, where number is the disk number of the UFD, and then press ENTER.