Linux is a cheap and stable operating system, based on Unix, originally written by Linus Torvelds in 1991. If you have at least 10GB free hard drive space on your computer, you can try it out, without affecting your current Windows operating system. The key here is not "Dual Booting", but instead, create a Virtual Machine, and install linux on that.
Contrary to popular belief, there are a huge number of computers that run Linux. Most of the servers that host web pages are linux-based. It is not totally 100% secure... but if you compare it to Windows, and the number of viruses, trojans and other malware that are currently available for Windows, it is extremely secure and robust.
It's not Windows Compatible
Programs designed for Windows will not run on Linux. There is a windows emulator called WINE, but you should assume that your favorite programs will not run using the emulator.
If, all you are wishing to do with your computer is word-processing, browsing the internet or email then you should seriously consider Linux.
OpenOffice.org is a free Open Source office package containing word processor, spreadsheet, drawing and presentation programs. Not 100% compatible with Microsoft Office, but it is close.
Firefox from http://getfirefox.com/ will allow you to surf the internet.
Why Linux will never beat Windows
There are two big reasons
* there are too many Linux Distributions. There are thousands of top quality programmers, who are able to understand the source code to constantly improve and secure the basic linux operating system, but their focus is spread over all the various versions of linux.
* Software companies who write the programs for you to use do not believe that there is any demand for their product from people who use linux. They believe that people who use linux are those who will not spend money. They are also influenced to use proprietary compilers that will only generate code for Windows-based computers