I'm trying to transfer Win10 installation from a HDD to a new SSD. I'm more or less following these two great howto's

That is, I've booted to winPE, then I've used XCOPY to copy boot, windows, users, program files, and such to the new disk, then I tried both bcdedit and bcdboot. However, in all cases, after booting from the SSD, win10 will bluescreen with the "inaccessible boot device" message.

Am I correct to assume windows gets through the initial boot (so BCD is okay) but then fails to load the kernel for some reason? Does anyone know how to debug or fix that?

I've tried things like auto-repair of the boot sequence via win10 recovery, but didn't help.

Not looking for "disk clone" (not enough space) and "clean install" (I know I can do that) answers, I'd like to try this way first.

Edit: Figured it out (see answer below). Why I did it this way? I wanted to learn. I find it more fun this way, rather than doing some backup-shuffle-shrink-dance. I didn't need to use the system right away and I had backups.


OK, I gave this whole thing a second go and - success! I'm not sure what I did wrong the first time but here's how I did it the second time:

  1. Created only one big partition on the new SSD, with MBR (not GPT) scheme
  2. I downloaded fastcopy to my winpe and used that instead of xcopy (mainly because of junctions): https://ipmsg.org/tools/fastcopy.html.en
  3. Removed BCD on the new disk, and used bcdboot instead of bcdedit to create a new boot config with the correct drives
  4. Finally, and this was one of the crucial steps, from winpe, I changed the drive assignments to make sure the new SSD is C: (via regediting HKLM\System\MountedDevices) in the new windows dir.

Then reboot and ta-dah! Running from SSD.


You can't just do a bcdboot to fix everything.

First, take a backup of your existing drive and make sure the backup works.

Your best bet is to install Easeus Backup Free, do a backup, and then do a restore onto the new SSD. Easeus Backup will allow you to resize down the partitions to fit on the new SSD. This is your best option because A) you've made a backup and B) you're not doing anything destructive to your working hard drive.

From the Easeus Backup documentation, "If the size of destination disk is different from the source one, then EaseUS Todo Backup will automatically resize the partitions before restoration starts, or you can edit the size by yourself.": http://www.easeus.com/support/todo-backup/disk-partition-recovery.html

You can also use the built-in Windows Disk Management utility (or if it can't srhink it enough a gparted boot disc) to shrink the partition down smaller than the size of the SSD, and then do a clone of the disc with the free software Easeus Disk Copy. Ignore any warnings about the destination disk being smaller than the source disk - as long as you've used gparted to shrink the partition to smaller than the SSD, then there's no actual data in that portion of the disk and Windows will just run a checkdisk on next boot and everything will be fine. This will only work for BIOS systems (running an MBR disk type). UEFI/GPT partitions will not like this at all, and you'll most likely end up with an unbootable system, so TEST YOUR BACKUP FIRST.

If neither works, you can do the most drastic option (again, make sure you have a working backup as about 2% of the time sysprep won't work correctly and will instead leave you with a Windows that doesn't boot all the way). Shrink the windows partition first on the old drive (to make sure the partition is smaller than the SSD). Then boot your working old drive to Windows, Run sysprep from C:\Windows\System32\sysprep.exe and choose the "OOBE experience" and check the "Generalize" checkbox and "shutdown". Once the shutdown is complete, you can then boot to Easeus Disk Copy and clone the drive to the SSD, and then remove the old drive and boot the SSD. Windows will go through its normal installation/initialization driver steps, and upon logging in with your old username (do note that the Windows installer will make you create a new username, but rest assured your old username is still there), everything will be exactly where you put it.

A fourth option also exists involving using DISM.exe to capture a .wim image of your existing windows installation and then applying it to the SSD. It's very involved and just about everything is via the command line; but this is the method your computer manufacturer used to get Windows 10 onto your laptop in the first place.

  • Thanks for the answer. I looked up Easeus backup and it seems you're right that it could've solved the prob. Then I thought that if they can do it, so can I. Great learning experience. :-) – user3227679 Nov 13 '16 at 16:11

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