Hello;
I see you have gotten a lot of good information about the various operating systems.
I would like to say a few words about Linux ...
Some people say that linux is for hard core computer geeks. To be honest with you there was a time when that was true! When I first got involved with Linux 10 years ago it was difficult to install, it was limited in its use and it was impractical for anyone who wasn't a professional.
Since then things have changed ... Linux has been redesigned to a great degree. The distro of Linux called Ubuntu is very easy to install and run. It is not for geeks anymore. I recently installed it on a computer novices machine and he won't go back to MS Windows if he could get it for free.
Ubuntu has a simple GUI interface similar to MS Windows ... programs run fairly smoothly. One of the big boosts for Linux has come with big companies usinig it -- Hewlett Packard, Dell, IBM, Google and others have made a point of supporting Linux when possible.
In Europe and Asia Linux is becoming the dominant Operating System. China has its own distro of Linux called Red Flag Linux based on Red Hat Linux.
How did this happen?
MS DOS and MS Windows were designed to run on very inexpensive systems that were weak. The idea was that the system would work and be usable by everyone -- thus it could be sold to large numbers of users.
Linux was designed by computer people who wanted the best operating system they could create regardless of sales. In fact most Linux distros are free! The upshot was that Linux has always used more system resources then MS operating systems and that it has been more complex. It was designed to have excellent security from the beginning.
Nowadays with computers becoming more powerful the system resources issue is not that important. Linux uses less resources than the Microsoft operating systems.
In the end there are some things that MS Windows does very well (Multimedia, and some trivial programs). Linux can do most of those things too, but sometime with some problems.
For "ordinary" computer work (e-mail, word processing, spreadsheet, and database work) Linux is just as good and sometimes better than the Microsoft products.
I hope you will enjoy using Linux ... it eventually comes down to a matter of personal choice.
Best of luck,
Bill