Most versions of Windows have something in the Control Panel that will allow you to make "backups." I put that in quotes because there are backups, and there are backups. Different degrees of thoroughness are required for different purposes.
The first rule to never violate is that backups should not be stored on the same machine which you are backing up. So you need another piece of hardware on which to put your backup files. This hardware could be as simple as a USB memory stick, a DVD disc, or an external hard drive that is connected to your computer. Getting it there and back when you need it is the hard part to put in simple terms. ;)
The simplest way to make backups for you would be to get yourself a memory stick or two that you can plug into your computer. Then just save a copy of what you want to preserve onto the memory stick. Drag and drop is good enough for most purposes. Take the stick out and put it in a safe place when you are done. Repeat this as often as necessary. If your computer crashes or gets stolen, then you have a memory stick full of information that you can simply copy back to the new computer.
The Control Panel app that Microsoft supplies does all this automatically. You still need a place to put the backup, but the software in your computer will do it automatically once you tell it when and where. Yes, I'm sorry to say, there is some setup required to make this work. There are also some very good programs you can download for free that will do more than what Microsoft will do, but you are asking for trouble if you have too many choices.
To answer your question about a dead screen on your computer, you will have to fix that problem first. It may mean a new computer or replacement of some critical parts. Once all that is repaired and working, then it's time to drag out your memory stick, or start up the backup program you used in the first place, to restore what is missing.
Simple?