>>>The current one suggests I run Linux instead of Windows 7
What a stupid comment for that newsletter to make, it is like saying you should drive a Ford rather than a Vauxhall.
Lets look a some basics:
Every PC computer needs an operating system, the most common one is Windows, but there are others, including Linux.
Now because Linux and Windows are different there are a number of things to consider.
1) A program that runs on Windows may not run on Linux. So if you have bought a computer program that runs on Windows, and then move to Linux, it probably wont run.
2) Operating Systems need "drivers" to make them work with hardware like Printers. Every printer sold will have drivers for Windows, but not every printer will have a driver for Linux, meaning it may not work.
3) Linux is developed by the computer community, so is essentially free, but loads of different companies package it so there are loads and loads of "versions" of Linux, all different. You need to deicde which one us right for you.
If your computer is running Windows 7 with no problems, and you are happy with it, then stick with it. It would be the same with your car, if your Ford is running fine and you are happy with it, then dont sell it and buy a Vauxhall or Toyota or whatever.
However, there are ways of trying Linux without having to remove Windows 7, and one of those is to run it direct from a CD. I am sure one of the Linux experts out there can tell you where to get it from.
p.s. Dotn get too hung up on Operating Systems. They are just there to get the computer to work, and support all your hardware etc. It is what you DO with a computer, not what Operating System you run.