What to backup

Ideally everything on the system is included in a backup scheme. But issues of cost, convenience and time may make this impractical.
We recommended backing up only those files that cannot be easily replaced.You only need to backup important user files, not program or system files.Generally, these are files that you create and safe to your hard drive.Files you created will usually have a name that you assign.If your computer crashes,you can restore programs and the operating system from the original CD-ROMs.Your important user files can be restored from your data backup copy.

For example, do backup your personal files: created and/or named by you,difficult to replace, like your financial files, used frequently like your internet bookmarks, priceless like your digitals videos and photos.
Don't backup program files: application or program files(files with the .exe, .dll, or .ini extensions), temporary files (files with the .tmp extensions), scan disk error files (files with the .chk extensions).

After you select what data need to be backed up, you need to choose the most appropriate data backup method for you or your organization, which can reduce the period of time for backing up and restoring your data.

Hard Drive Backup