I recommend you try Linux with a Live CD (won't change anything on your system) and if your are satisfied, don't erase Windows but install Linux alongside Windows. You can be given the possibility of choosing which system to use at boot time (this is what is called "dual-boot"). This is simpler and faster than to run Windows in a virtual machine. Only caveat is at a given point of time you will be using one of the two systems, not both.
Whilst I personally prefer Slackware I suggest you install Ubuntu which may be easier for beginners. See this page