1.5GB must be allocated to one partition for installing WinPE boot environment and the rest of the available space is allocated to another partition saving a master image file.
The created master image is compressed before saving. About 70% of the backup source volume is required.
For example, when the used space for C: drive is 30 GB, the backup image size is about 21GB.
* Depending on the environment, the master image file may not be compressed as small as expected.
As a result, USB memory needs to have 32GB or more available space.
– ActiveImage Deploy USB