Windows Vista attempts to save registry by routing all write edits (new key, edit existing key) to a storage folder. No hope on defending delete keys yet. Registry remains nearly totally uniform in overall architecture on all Windows machines. These edits can be performed by web sites and e-mail attachments. The very concept is not possible to Unix kernel, and there is no universal admin/root user password, root kits are almost eliminated in all Linux Distros. That's all I have to say on this topic.