Disaster can strike at any time and computers are just machines that are not immune to failures or technical glitches. In the unfortunate even that your data does become inaccessible you want to ensure that you have a backup copy that you can revert to. Most modern operating systems come with backup programs built in. Windows 7 has a Backup and Restore utility while Mac OS X has Time Machine. You do not, however, need any specific software to start backing up your files.