After my friend got the "cryptolocker" virus and has lost all of his important files I have decided to back up everything on my laptop, it is running win XP (old I know but I like it) somebody gave me a WD (western digital) external hard drive but I have not got the faintest idea how it works or how I back up my files so any help in laymans terms would be most helpful. Thanks.
broadly speaking, you'd plug it into your computer and it would show up as a drive when you click on My Computer. Then you'd just highlight everything in your documents (or whatever you want to copy)_ and drag it over. Check that it is actually "copying" not "moving".