Taking regular backups of your data is the same as having house insurance - you only need it when something gets broken.

Think about all the data you have generated on your PC - letters, spreadsheets, household and business accounts, emails, internet favorites, contact names and addresses etc. etc.. Now imagine that you have just switched on your PC and you get a series of beeps and a message stating 'Hard Disk Invalid'. You can install a new hard drive and re-install your operating system and all your software, but all your data is lost.

At best it can be time consuming and inconvenient to re-enter all your data, however if you run a small business and you lose all your customer records, invoices, payments etc., it could cost you thousands of pounds in unpaid bills and lost work. 

Your backup strategy must be to ensure that you have copies of all data that is important to you. This can be achieved by coping your data to an external hard drive or if you have a large amount of important data, to a tape drive. It is also important to think about fire and theft by ensuring you have a copy of your data held offsite.

Refer to your system help files for more information on backups.