@
ittiandro here is an alternative way to make the image available for restore that does not require networking. It's a little more complicated though. We are going to make another virtual disk, copy the image file to it, then attach the virtual disk as a second drive for the VM.
First make a new virtual disk. Open Disk Management. Click Action > Create VHD. Choose to make an expanding .VHD, and a folder and filename for it (C:\temp\images.vhd in my example). Make sure you create a .vhd that is large enough to hold your image file.
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Next you need to initialize the new virtual drive. In Disk Management right-click on the name of the new drive, the grey box to the left.
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Choose to initialise as MBR. Once initialised you can right-click on the drive to format it and assign a drive letter.
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Now copy your system image to the drive using File Explorer. When done you need to detach the virtual drive, you can do this in Disk Management.
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Now we can attach this .vhd to the VirtualBox VM. In VirtualBox Manager select Tools and click the Add Disk icon (green + sign). Browse and find your .vhd file.
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Then open Settings for your VM. In Storage select the Controller: SATA and click the right most of the two 'add' icons to add a new hard drive.
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Now when you boot the VM from the recovery ISO you can browse to this 2nd hard drive and select your image.
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Once you have successfully completed the restore you can detach the images.vhd from the VM, then delete the .vhd file now it has served its purpose.