It is possible to try Linux without touching Windows. Thus, you can get used with Linux and see by yourself how nice it is.
You need to download an ISO image and burn a CD, then restart the computer with this CD. Then you will be able to modify the Desktop, browse the web, send emails and listen to music without any fear, since everything will have disappear after you restart.
This is called a "Live-CD". You can try one of the two following distributions :