Assign new uuid to Virtual Box Harddrive

I recently had to copy a  VirtualBox HD image and didn’t use the build-in support which resulted in problems with UUID’s not matching or being duplicates of each other. To solve this I used the following command to generate and reassign a new UUID to my disk copies.

VBoxManager.exe internalcommands sethduuid image.vdi

for newer versions:

VBoxManage.exe internalcommands sethduuid image.vdi