Although I prefer Linux as Desktop OS, Gaming on it is still very hard to realize. That’s why I need a Windows installation on my system. Said installation didn’t age well, so I decided to rejuvenate my six year old Windows installation and install Windows 10.
I wanted to have a fresh start and didn’t want to keep anything, but I still wanted to retain my old system and data partition as backup. I decided to use a Virtual Hard Disk (VHD) file as backup format. The advantage of this is that I can easily boot up a VM to compare my old system with my new one. Additionally Windows 7 natively supports mounting VHD, enabling easy access to the files. Thus, I created a step-by-step instruction for later reference.
For this process you will need about twice the size of your partition as disk space. The resulting image will be roughly the same size as the original.
Of course I used Linux to do all of those steps. If you don’t have a Linux installation, use a Live USB stick with a distribution of your choice.
unmount the partition you want to backup if it’s mounted
use ntfsclone to create an image excluding unused partition space
Update 2016-03-18: I removed usage of the -s switch because it makes the resulting VHDs unreadable.
Install VirtualBox if not already installed, we need VBoxManage
Use VBoxManage to convert the ntfsclone image to a VHD
This process may take some time, but afterwards you have your VHD backup ready to go.