Not to sound rude here But before getting into networking it is a good idea to learn computer Operating systems and there various tools and the hardware.
Good luck though in your studies and hope you do well.
But to your question.
There are a couple of ways to back up your system.
Windows has a backup tool in Start - accessories - System tools
Or
You can use a third party software like Norton Ghost - Bounce Back - EZ Gig.
that will make bootable backups.alot of people like Norton ghost to create an image of there drive.but it is as anything else it is what you like.I myself have 5 backup drives yes 5 lost everything once (Keyword "once").all important files i copy to all the drives.the only thing is determining what type of back up.
Check these.
http://www.geekgirls.com/windows_backup_strategies_table.htm
http://www.novastor.com/tech_supt/Procedures.html
Hope this helps if not Please let us know will help further.
Thanks