Here is the workaround I have tested when you get INACCESSIBLE BOOT DEVICE with the target device when you try to migrate W10 (using any Copy disk or OS migrate Third Party Tools available).
(Tests done with UEFI BIOS, BIOS CSM Disabled and Boot Secure activate Options, Migration from NVMe device to SATA device AHCI mode or from SATA device AHCI Mode to NVMe device).
Generally when you try to migrate W10 from one Source media to a Target device and and then try to the Reboot with this one (after removing the Source device of the PC) you get a BSOD with the error message:
INACCESSIBLE BOOT DEVICE without any Stop Code value indication.
To get finally your target bootable device you have to let the timeout (about 10s) running.
Wait for the Second Apparition of the same BSOD.
Wait for again the second timeout again (about 10s).
Then an automatic offer does appear such as: "Prepare automatic Repair".
Wait for "Diagnostic Computer"
then select (quickly before a 10 s delay) -> Advanced Options -> Repair -> Advanced Options -> Parameters -> Restart -> Starting Parameters -> Press on F4 on keyboard -> Save Mode -> Restart -> Boot should be OK.
Then Stop W10 -> Restart PC -> Finally the new Target device does boot in Normal Mode without BSOD.
@100PIER :
Thanks for your report about the “INACCESSIBLE BOOT DEVICE” issue and the given workaround.
@all:
Another option to avoid the issue is to do a fresh OS install onto the target SSD/HDD, if you want to change the system drive (with the OS on it).