# Using DD to copy a Windows installation



## balanga (Jun 26, 2016)

Can I use DD to copy a Windows installation to a new disk?


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## wblock@ (Jun 26, 2016)

Yes, if the new disk is the same size or larger than the old one.  If it uses GPT partitioning, the backup GPT table at the end of the disk will probably be in the wrong place unless the disks are exactly the same size.  gpart(8) can fix that.  Whether Windows will like that fix, I don't know.  My experience is that Windows partitioning and disk layout is remarkably fragile.

I would use Clonezilla, which will handle most of the problems and do it more quickly than dd(1).


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## Jeckt (Jun 27, 2016)

Just to confirm this, I've used dd to copy windows (7) installs. I can't recall what windows thought of the backup GPT table missing, but it booted fine. Running the disk utility in windows allows you to then grow the NTFS partition to fill the disk if you've transferred to a larger hard rive.


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## wblock@ (Jun 27, 2016)

Windows 7 is almost always an MBR install, so it is not a problem.  But dd(1) copies the entire disk, so it generally ends up wasting time copying a lot of blank space.


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