Hi, I've been wanting to completely wipe my internal hard drive on my iMac and reinstall Windows XP and Mac OS X. As things have become pretty cluttered and I'd like to start over completely and install only the things I want. A couple questions I have are: 1. Can I use disk utility to create a complete backup of my hard drive, both the Windows and Mac partition, and in case things go wrong use that to simply restore my iMac? 2. Is their a good way to keep all the registration information and serial codes from my old installation's users? I really don't want to go look up 50+ serial numbers for different applications. But I do remember having success copying the user information and simply copying them to my recently installed information, would that still work? 3. Can I install Ubuntu 9.10 onto an external hard drive and boot from that if I would like to? I'd like to have Ubuntu there for fun and debugging purposes. Thanks to anyone that puts up with these questions and helps me out.