Since your entire hard drive is likely to be much larger than the amount of storage you have purchased on the backup server, you should be selective in the files that you choose for backup. In general, you can avoid backing up any programs that you can reinstall from a purchased CD, such as Microsoft Office (Word, Excel, etc.). Why pay for storage for "stuff" you can easily re-install? Try to focus your selection on things like your "My Documents", "My Pictures" or "My Music" folders and data files of your important programs like accounting, income tax, contact management, etc. Your online backup software comes with predefined filters, which allow you to automatically select categories of files without knowing where all the files are located. See the software's Help section on Filters to learn how they can be used.