Blancco Preinstall MSI supports booting on encrypted hard drives, but it is required that the drive encryption software doesn't encrypt newly created drive partitions.
In order to boot up the Blancco software, Preinstall MSI package will create a temporary drive partition which will be used to boot up the software upon next reboot. If this temporary partition is encrypted by a third party software, it is not possible to use it to boot up Blancco Drive Eraser. As the encryption is done by a third party software, it cannot be bypassed by Blancco software.
If booting Blancco is failing with Preinstall MSI package on encrypted devices, please check the encryption software settings to make sure that any newly created drive partitions are not being encrypted. For any further questions, don't hesitate to contact Blancco Technical Support for more details.