I have many customers who have experienced data loss due to hardware failures because they had not backed-up their important data files. 

Every computer hard drive is going to fail, it's just a matter of time. 

Operating systems and software can be reinstalled but your precious digital photos, important documents, email messages/addresses and downloaded music files can be lost forever when your hard drive crashes. 

I recommend that you try Mozy which offers a *free data back-up service. I use this service because of it's ease of use. Once configured it works automatically in the background backing up your important files to their secure remote storage servers. It automatically backs up any new files you add and also any changes you make to your existing files. It is one of the highest rated services of its kind on the Internet.