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Unable to boot after cloning C: drive - BSOD

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Hi everyone!  Hoping someone will be able to help me out.

Basically, I used ATI 2018 to clone my C: drive (a 1TB m.2 PCIe NVMe drive) to an external hard drive. I have done this before without any problems. This time, as the clone completed, instead of getting some sort of "cloning complete" message, the computer rebooted. Instead of Windows starting, it went right to the BSOD and gave a message of "kmode exception not handled." After a few seconds, it rebooted again, and again, the BSOD.  Rebooted again, and so on.

I have tried to boot to the C: drive, the external drive, and my Windows 10 USB Recovery Drive, all with the same results. Every couple of attempts, I get a "Preparing Automatic Repair" message, but that too results in a BSOD and the computer just reboots.

The computer is a laptop, a Sager NP7877DW, running Windows 10 Pro 64-bit.

Not sure what else to do at this point. Thanks in advance for any suggestions!

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Clinton, welcome to these public User Forums.

The first recommendation here is to disconnect all external drives from your laptop.  Microsoft do not permit Windows to be booted from any external USB drive unless you have purchased an Enterprise edition of Windows and are using their Windows2Go feature.

Next, do you have a Disk backup of the internal 1TB NVMe drive?

Try rebooting the laptop with only the internal drive and if this goes into the Windows Recovery panel, then try doing a Startup Repair to see if that corrects matters?

If the laptop still won't boot then you will need to have a copy of the Acronis Rescue Media to boot the laptop from and a Backup image to do a recovery from.  This is where Backup & Recovery will always win out over using any Clone method unless you are intending to remove the Source disk drive and replace it by the Cloned drive but with laptops this is not guaranteed to produce a bootable system.

Please see KB 56634: Acronis True Image: how to clone a disk - and review the step by step guide given there.

Note: the first section of the above KB document directs laptop users to KB 2931: How to clone a laptop hard drive - and has the following paragraph:

It is recommended to put the new drive in the laptop first, and connect the old drive via USB. Otherwise you will may not be able to boot from the new cloned drive, as Acronis True Image will apply a bootability fix to the new disk and adjust the boot settings of the target drive to boot from USB. If the new disk is inside the laptop, the boot settings will be automatically adjusted to boot from internal disk. As such, hard disk bays cannot be used for target disks. For example, if you have a target hard disk (i.e. the new disk to which you clone, and from which you intend to boot the machine) in a bay, and not physically inside the laptop, the target hard disk will be unbootable after the cloning.

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Hi Steve!  I wanted to thank you for your reply.  I've been through quite the headache over the past few days, and I greatly appreciate all your suggestions.

I had tried disconnecting all external drives, but that didn't help. I had also tried the System Repair option, but it said there were no issues it could fix automatically.  I ended up coming across this discussion, Dangers of cloning where you talked about what happens when the BCD file gets changed during the cloning process and doesn't get changed back.  Well, this is apparently what had happened.  I was able to boot to a Windows Recovery USB drive from another computer (I don't know why the one from this computer wouldn't work), and then from the command prompt was able to rebuild the BCD file.  After this, the computer was able to boot to the internal C: drive, and everything seemed to be okay, at least with the C: drive.  But as for the external drive, I could not ever access it, even if I wasn't trying to boot from it, so I assumed the clone had failed.

At this point, I had not created an Acronis Rescue Media drive, so I decided to do that, to try cloning from that instead of from within Windows.. Well, when I tried to boot to that, the laptop's screen just turned white, and the machine locked up.

So, then I decided to upgrade my ATI 2018 to 2021.  I was able to set the clone procedure up, but after it started, the progress window never changed.  It just said "Preparing," and "Estimated Time Left:  Calculating Time Remaining" and never seemed to do anything, even after I let it run for about 4 hours.  I then created an ATI 2021 Rescue Media, and I honestly don't remember what happened, I think the same thing, just no progress.

I understand the recommendation of putting the old "master" drive in the external enclosure, and the new "blank" drive into the laptop.  Unfortunately I cannot do that as the drive I am trying to clone to is a 3.5" hard drive.  So, I'm thinking that's the root of my problems.  The thing is, I had cloned my old laptop's internal drive (originally a 2.5" traditional hard drive, then later a 2.5" SSD) using the same method for years, and was even able to clone the C: drive in my new laptop successfully back in June using all the same hardware.

I like to have a cloned drive so that in the case of needing a new hard drive, I can just use the clone to restore to in order to save having to install the OS and all the different software.  In the case of my current laptop, I have a second internal drive that I use for all my data files, so backing that up has not been a problem.  So, keeping a clone of the C: drive is not a necessity, just a convenience.

I'm thinking my best bet is going to be picking up another m.2 NVMe drive along with an m.2 external enclosure (which I just learned today exists....).  I then would take out the internal drive, put it in the enclosure, put the new drive in the laptop, clone the external drive to the internal one using the Acronis Rescue Media drive, and then just keep the external drive stored away as my preserved drive.

Well, thanks again for your help!  I'm happy to at least be up and running again.

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If you want a quick way to recover from a failed OS drive, I would suggest creating a full disk backup and recovering the backup to a new drive if and when the OS drive fails. I use backup and restore when migrating from SATA SSD to an M.2 NVMe SSD, and when upgrading M.2 NVMe SSD. There are far too many unexpected gotchas with cloning, particularly when trying to clone to a USB connection which will result in an unbootable drive: 45831: Acronis Software: Unbootable System after Cloning Operation.


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Thanks, Ian!  I will look into using a full disk backup instead of cloning.