Do you know that there's a new computer "brand" that will probably eclipse Microsoft and Apple over the next ten years? It's called Linux. And it actually isn't a brand, it's a project where amateur and professional computer programmers from around the world contribute their work for free. Because no one is on a salary, the end product is also free of both cost, and restrictions. Programmers like Linux in the same way that auto mechanics love old chevrolet and ford cars - they can open it up, look under the hood and see how it runs.
If you're curious about it, and you have a high speed internet connection, and you know how to write a disc image (.iso) to a compact disc, and you know how to set your computer to "boot from" the cd/dvd rom drive, I would recommend that you try out one particularly fun version. This is a version of Linux called "Puppy Linux" - and this particular release comes with very cool animations and transparencies that are even better than what Windows Vista gives you. You'll see it's still a bit unstable... kind of like Windows '98 was... but it's fun to take a look at anyway.
(This compact disc gives you a chance to "test drive" linux. Booting it up certainly won't change anything on your computer, so it's completely safe. The maker of puppy linux - Barry Kauler - actually recommends that you run it either from the cd, or from a usb memory stick - if you have a spare one of those around, you can install it to that, and it will run very quickly)