I have had my laptop for 15 months. I have not made a copy of anything. Is it possible to make a copy of everything I have done on the computer, and. if so,. how long should it take
you could copy it on to CDs or get an external hard drive which you only plug in when you want to use it. That way if the laptop crashes you still have copies of everything, which is a good idea. How long it takes depends how much you have to copy (might be an hour or so but it could be longer if you've got lots of files).
You could see if you can pick up a copy of Ghost or Acronis software - they will let you make a clone copy of your entire HD, so that if something does go wrong, you have a total back up copy