A while back I had a bit of a chat here with a certain Non-Dave (haven't seen him around much lately) about switching a computer over to the Linux Ubuntu operating system. I finally took his advice and did it. It's great! I'm not sure I would necessarily recommend switching a new computer over to it, but what it's totally brilliant for is rehabilitating an old, slow and cranky machine. A six-year old Dell laptop which had been gathering dust since I abandoned her for a younger model is now back - lean, mean and very fast. Using free software which you can import directly from a window similar to the Apple app store, I can do everything I need to do, including reading/creating Microsoft Office documents. My old laptop can now serve as a knock-about to take on trips etc., and I won't be heartbroken or seriously inconvenienced if it gets lost/stolen/damaged. And with no virus issues to worry about, you don't have to bother with installing/updating antivirus software. The link for more info:
http://www.ubuntu.com/