It's your data versus the world.
Computers get stolen and sometimes catch fire; this can cost you your irreplaceable data and documents. Computers crash, it's a fact of life. And sometimes, simply rebooting doesn't fix things. Disk failure can lead to a complete loss of all the data on your computer.
Backing up your data is a basic preventative measure that will keep you from pulling your hair out. Use a Zip disk, USB flash memory stick, recordable CD or DVD, to save what you really wouldn't want to live without.
You can also utilise online services that automatically back up designated folders and store them remotely and securely.
For a security solution that includes online backup Madasafish recommends the following software: