For some file system faults you may be able to as long as:-
1. The device is not at, or close to, the point of mechanical failure. In these circumstances you will almost certainly damage the disk further.
2. You are a fairly proficient computer user.
We often receive disks when the owner, or their computer technician, has attempted recovery and in the process reduced or completely eliminated any prospect of successful recovery. If your data is critical we recommend engaging a professional data recovery company.
Software recovery tools downloaded from the internet are only suitable for recovering from minor software problems. Even some of these tools are completely ineffective.
If your car engine was broken would you attempt to fix it yourself? Hard disks are much more sensitive.
Never install recovery software to the disk itself.
For CD or DVD recovery, where the media is not physically damaged, please download an evaluation copy of IsoBuster. It will display what data can be recovered before you need to purchase the product.