The job of a technician tasked with recovering data from a heavily damaged disk is similar to that of a restoration expert working on an antique or historical document. The goal is to recover as much valuable information as possible while keeping the original source material intact. Likewise, data recovery technicians and antique restoration professionals share a best practice for achieving this objective: handle the delicate object as little as possible.
When your hard drive becomes corrupted or physically damaged, every action you perform on it can cause the loss of more data. Think of your hard drive like the original Declaration of Independence. It's important to study the contents of the document, but it doesn't make sense to roll out a 300+ year old piece of historical parchment onto your desk to do so. That's because every time you fold or unfold the document, you are degrading its integrity and destroying irrecoverable bits of history. Instead, it's just as prudent to make a copy of the document and study that.
It's the same with your hard drive. When there is a physical defect in your hard drive, say with the read/write arm, it usually means that each time you read or write to a sector, it destroys it. That means you only get one chance to recover the file. So, if you open the file to preview its contents and it becomes irrecoverably damaged thereafter, you've missed your opportunity.
You'd avoid this situation in the same way that you'd avoid damaging the original Declaration of Independence while studying it: make a duplicate. Creating a disk image is much less invasive than reading/writing to a disk normally, and you only have to do it once. Your first step when attempting to recover data from a damaged disk is to use the Imaging module of R-Studio to clone the disk. Then, you would perform your intensive data recovery operations on the disk image, rather than the original disk.
This has a number of benefits. First and foremost, you don't cause any further damage to the original hard disk. Cloning a disk performs damage control, putting an end to any further degradation or loss of data. Secondly, reading from a disk image is much faster than attempting to read from a faulty hard disk drive. Just like a vinyl record skips when it gets scratches, your computer will stumble when it encounters a bad sector on a hard disk drive. It'll attempt to read and re-read the sector multiple times before declaring it damaged and then moving on. Not only can this cause further damage to the drive, but depending on the size of your drive and the extent of the damage, it could take hours to go through the whole disk in this fashion. By creating an image, you only have to do this once. Lastly, disk images are more portable. Rather than physically removing the hard drive and attaching it to another computer, you can simply load the disk image onto a removable storage device or access it via a network connection.
Bottom-line: Your first step when recovering data from a damaged hard drive should always be to clone the disk. It'll save you time and increase your chances for successful data recovery.