Backup Software

I am looking for a free Backup software which is simple and will allow me to find specific files and/or directories, hopefully in a way similar to Explorer. Does anyone have a suggestion. I recently had a complete system crash and lost all my stuff. I bought a 500gb external drive but I don’t trust the backup program as there was no documentation which came with it. P.s. I have Windows XP Home on a Laptop. Thanks in advance, J