It's inevitable: At some point you're going to need to recover from a disaster. You'll have a hard drive fail and either you'll lose valuable data or the machine will refuse to boot. When this occurs, if you happen to have a disk image, the task will be far easier. But many budgets don't include the cost of some of the pricier disk imaging software, like Acronis Backup and Restore. When you don't have the budget, what do you do? If you're lucky, you have access to one of these free applications, all of which do an admirable job of cloning a hard drive.
Some of these apps are more powerful than others. While some will do a-bit-for-bit copy, others create a full ISO of your running system. Some are Windows specific and others don't care what platform you're running. In the end, what's important is that you use the tool that best suits your skills and needs.
SEE: 5 free and reliable cloning tools (TechRepublic)