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I have a Lenovo Windows 7 laptop with an MBR hard drive I want to clone. I used a Linux (Kali, FYI) live USB stick, booted on the PC and used dd if=/dev/sda of=/dev/sdc bs=100M conv=notrunc to clone the internal HD to one connected via USB.

As far as I can tell, this all worked fine and from Linux I can access all the data on all the partitions. However when I rebooted into Windows to test it, Windows doesn't seem to recognise the drive. It plays the ge-dunk sound when I plug it in, but nothing appears in the list of drives when I go to "Computer".

I am not at all familiar with the workings of Windows, but I am familiar with Linux. I also tried plugging the drive into an OS X machine, and that was recognised just fine too.

How would I go about troubleshooting this within Windows, as I will need to access the drive from Windows at some point.


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Are you trying to boot the cloned drive as a windows drive? If so, the dd only copied the OS/data partition, not the boot sector. If you aren't booting it, what happens when you use the windows disk manager to view the partitions? Does it show the partition type from there? – jdh Apr 3 '13 at 14:13
@jdh, in Disk Management it shows the disk is "offline because it has a signature collision with another disk that is online". I imagine this is because it is a clone of the internal disk. – bountiful Apr 3 '13 at 14:18
@jdh, ah ha! If I right-click and choose "Online" it mounts it! – bountiful Apr 3 '13 at 14:20
@fophillips Some sort of signature or ID collision was my guess. You should perhaps flesh that out a little more as an answer and post it; though this isn't exactly an everyday scenario, someone's bound to hit it. Also, it might be useful to state whether the drive is MBR or GPT. (Static/dynamic disk or whatever Windows might call it.) – Michael Kjörling Apr 3 '13 at 14:27
up vote 3 down vote accepted

This seems to be caused by a signature collision between the two disks, as one was an exact clone of the other.

This can be fixed using Disk Management within Windows (accessible by Control Panel -> Administrative Tools -> Computer Management -> Storage -> Disk Management). Within this you can see that the drive is offline. By right-clicking on the drive and selecting "Online" this will force the drive to mount all partitions despite the signature collision.

I don't know if this will cause any collision related problems, but I have yet to run into any.

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