Easy disaster recovery, in computing as in life, requires forward planning. This means making regular backups of your computer, and checking that those backups work properly.
The actual backup process is covered in Chapter 30, "System Maintenance," but here we discuss the other aspects of disaster recovery.
There was a time when PC floppy disks were 360KB and hard disks were 10MB. A complete system backup might fit onto 30 floppy disks. A few years later, floppies were 1.44MB and hard disks were 100MB—that's over 60 floppies. Today, floppy disks are still the same size but disks are 4GB. Even if you could buy 3,000 floppy disks, system backups would be ridiculously impractical.
There are many solutions ...