I’ve recently come across a situation where I had an encrypted Samsung laptop that needed a reimage. The previous owner had encrypted the HDD so that no one who would find /steal the laptop could access the data from it, which made it difficult to even boot from the USB I wanted to use, as it always loaded the OS it had installed.

How to Overwrite the OS on an Ecrypted Machine

If you are ever in this situation, here is what needs to be done to make the laptop usable again:

  1. Boot the computer → BIOS
  2. Go to Advanced → Fast Bios Mode → set it to disabled (this will allow you the needed time to boot the OS from the bootable USB stick/CD/DVD you plan to use)
  3. Then go to  Boot Priority order and set them as follows:
    1.  USB HDD (the bootable USB I used in my case)
    2.  SATA HDD
    3. Ubuntu → disable it (this was the OS previously installed on the laptop – this step is optional)
  4. Reboot → Install OS
  5. Reboot → Advanced → Fast Bios Mode → Enabled
  6. Celebrate.

How to Overwrite the OS on an Ecrypted Machine

You could also install the OS from Live mode and use EFI mode to delete the previous record of the OS used, so that there wouldn’t be multiple entries of the same OS. What is mandatory for Samsung laptops is to disable the Fast boot mode and the order for boot devices to be set 1st for the bootable USB you plan to use, the purpose here being installing a new OS (be it Ubuntu or anything else).