1. In a computing system executing a hypervisor to provide a client virtualization environment, a method of managing a virtual hard disk tree, the method comprising: linking, by a client executing within a control virtual machine of the client virtualization environment, a first delta image of a virtual hard disk generated later in time to a base image of the virtual hard disk; modifying contents of the first delta image, the base image, and a second delta image which is linked to the base image; and after modifying the contents of the first delta image, the base image, and the second delta image, deleting the second delta image; and wherein the base image and the first delta image, together with additional delta images of the virtual hard disk comprise a tree of images of the virtual hard disk.