My computer went in to hibernation and I didn't know how to wake it up. I went to the computer store and they told me I had to reboot. I did and I haven't seen that information since.
That doesn't make sense. I've used Hibernation many times; the purpose of Hibernation is to power off your computer without having to close the applications you had open and then being able to immediately resume where you left off when you start your computer, i.e. bring it out of Hibernation. So, Hibernation is designed to save your data, not lose it.
I mean no offense but, for someone who is working with a large and apparently very important file, shouldn't you learn more about how Windows and your laptop computer work? And, clearly, you need to know more about backup options and how they work. If you want to burn that file to DVD, you need to learn how to do that.
Is there a computer user's group (CUG) in your area? A CUG could be very beneficial for you. Public libraries are another source of books and videos on computers.
I think buying a flash drive would be a smart move; a small capacity one, say 512MB or 1GB, should be fine for just backing up that file and other data files. Even larger ones are quite inexpensive now; rebates are sometimes offered. Visit a Best Buy, Staples, etc. store, or buy online from a website such as buy.com. For example:
Kingston 4GB DataTraveler USB 2.0 Flash Drive - DTI/4GB, for $16.23.