IMac Bootcamp to a external drive

I try to migrate my bootcamp to a external usb drive with a same IMac. It is successfully cloned but I cannot boot up. It can just launch to windows but many error came out. Do I really need to Sysprep before it?? I just run on the same IMac and everything is the same except it will be run on a external drive. Please advice.

External drive booting can be tricking. We created this article to help address the issues:


I do all the things in the following topic except the Sysprep, do I really need to do the sysprep for the bootcamp volume, It consume a lot of time of doing this and also make the origin copy of Bootcamp problem if the cloning fail again. I think the WinClone will fix this problem before purchasing it.

Which model iMac and which model USB drive?

What are the error messages that you get?

It’s recommended to save a bootcamp image before doing a sysprep and if that one doesn’t work then try a sysprep and use that.

2015-late year IMac, It just keep flashing after go into windows. It seems to be a driver problem.

I got the problem during Sysprep about the provision of some AppPackage installed in windows, also it may combined with the user permission in Windows. It is not a good way for me to fix this problem. It just make the problem bigger.
Should I just try to inject the driver about Clone the internal BootCamp to external?

I really don’t want the Sysprep Process. Is there any standard procedure about migrate the boot camp to external drive?

That’s what I did:

  1. Start the Mac from Windows 10 Bootcamp Partition (internal HD)
  2. Deactivate hibernate (search -> cmd -> run as administrator -> powercfg / hibernate off)
  3. Shut down Windows 10
  4. Boot Mac from macOS partition
  5. Copy the Bootcamp partition to an external SSD with Winclone, transfer the required drivers and EFI partition
  6. Shut down your Mac
  7. Restart the Mac from the internal Windows 10 Bootcamp partition
  8. Open regedit as administrator
  9. Click on HKEY_LOCAL_MACHINE Node and then click on the menu item “Import … Node”.
  10. Change to the external SSD in the selection dialog, navigate to the Windows / system32 / config directory and click on the “SYSTEM” file there. Now choose a name for the node to be imported (e.g. TEMP_SYSTEM).
  11. Click on the imported node and delete all entries and the associated nodes in the “MountedDevices” subnode. In addition, in the “HardwareConfig” node, change the value of “BootDriverFlags” to 14 (Hex).
  12. Remove the imported node in the Regedit menu.
  13. Shut down Windows 10
  14. Start the Mac with the Alt key pressed and select EFI Boot
  15. In (hopefully) running Windows 10, activate Hibernate again.

This doesn’t help for the problem.

I think the WinClone should handle some general cloning problem about bootcamp, but it doesn’t. It is a paid software but it doesn’t perform what it needed to be.