mohamedmostafa.co.uk
Create an image from a .vhd disk on Microsoft Windows Azure - error VHD is already registered with image repository | Mohamed Mostafa's Blog
This post discusses how to create an image from a VHD file of a VM you have on Windows Azure to re-use it with other VMs and also shows a resolution to the issue/error: "xxx.vhd is already registered with image repository as the resource with ID xxx" on Windows Azure management portal.