A number of methods that are available to store the data n the hard drive for safety like removable disks, CD, DVD etc are some of them. Whatever be the storage device any media is subject to risks and any mechanical and electrical error may occur anytime. However old or new the device, it may fail to operate properly and you cannot do anything to stop it.
Thus you can see that the hard drive impairment is quite natural and there are number of reasons for the failure of data lost like deletion of file due to accident and also natural damages like fire and water. For requirement of data recovery from hard drive which is caused externally you can use the normal simple method of retrieving data which only impairs.
The simplest recovery is the one in which the recovering process is done externally to the USB, Firewire etc., in all of which the data is not accessible directly and not through normal manner. These external hard drives can be recovered, but it needs a very specialized and exhaustive job to recover the data lost. But still like other normal ways, external methods also involve the same process of saving the files that are not accessible.
Prior to the external data recovery, the evaluation procedure is carried out. The external hard drive is measured and experts or technicians will provide you with initial detection of the level of damage along with its potential for the recovery of hard drive and the study involved saving the data required. Some of the organizations nowadays charge fees for the external hard drive evaluation. But still there are free services given by some providers which need to be checked.
After the evaluation or measurement carried out for the external hard drive recovery, an estimation of the whole process will be given by the technician. Apart from it, the data amount that has to be retrieved along with the steps needed and price of the service will be given .Thus these firms deliver some quotations to do the hard drive recovery.
Just after the evaluation along with estimation done, the next step is approval to continue with the actual data recovery of external drive. Only after approval done, everything else is carried out and once it is been done, the firm will do their best to get back the lost files to you. The good news is that they even repair the hard drive along with data retrieved from the drive. The data got back will be sent to you on whichever media you would like to get it.