I keep wanting to try a Linux system, then I read incomprehensible stuff like this. I bought a computer that had linux on it, and I, being raised on Windoze, was unable to launch much of anything, and I couldn't find stuff. I was lost. So I wiped it. I downloaded Ubuntu once, but something was amiss, and I gave up on it. The live OS on disk sounds promising, but not if I ever have to understand the above paragraph. Linux users, go ahead and laugh at me.
I tried Linux too. I had my XP system with a double boot option and fooled around with it. It’s good but certainly not better than Vista. Just pull the monitor and other equipment off the XP machine, stick a new Vista box in there ready and already loaded and you’re good to go. You will love it. I heard all the negatives and they were all wrong. It is a great system.
These work arounds and manipulating of old machines is silly. I would have spent more to upgrade my old XP system than I spent for a brand new dual core Vista system which I now have. It made no financial sense. And besides a 3-4 year old machine is functionally obsolete anyway. It’s time to move on anyway.
If you don't have network connectivity, you can go to the book store and pick up a variety of distributions with books and DVD ready to go. Alternatively, you can order almost any distribution from discountlinuxdvd.com. You'll have ready to use disks in your mailbox before you could download the images from a website. Dirt cheap as well.
It looks like a lot of new stuff to learn. It is. I've trained many UNIX system administrators since 1980. Some of them have already retired...and they were new employees. Even the bright ones require about two years of working daily to be exposed to all the possible issues and resolutions. It's a continuous learning effort as the field grows and changes. Learn what is most important to you first, then add new skills as necessary. You'll find lots of books on the shelf to guide your new interests.