Data Recovery Service Alternatives and the Risks Involved

When you contact a data recovery service, usually the first thing they will want to know is how the files you want to recover were lost. You might have accidentally deleted the files, or the data might have become corrupted. In a worst-case scenario, your hard drive might have sustained damage, ranging from relatively minor damage such as hard drive crash, to serious physical damage such as flooding or fire. However, the data recovery service most likely won't be able to give you a quote until they have inspected the hard drive, so you will also need to drop off or mail your hard drive to them.
Before the data recovery service begins work on your hard drive, they will make an exact copy of the drive. All work will be done on this copy, to avoid doing any more damage to the drive itself.
Using the copy of the original drive, the data recovery service then uses a variety tools and techniques to try to recover the lost data. Every hard drive creates a sort of table of contents at the very beginning of the drive; by retrieving old tables of contents, the data recovery service can tell where the files you need would be located on the drive, making it easier to make sense of and restore written-over data.
Once the data has been restored from the drive, the data recovery service checks to make sure the files they have recovered are complete. Again, they can use old tables of contents from the hard drive to check for holes in the files. Once they have ensured that the data is all there, they will back it up to CDs or another storage medium, and send it back to you.