Data recovery is not always worth paying lot of money for. You can even recover the data yourself in the comfort of your own home using some free software for example if you lost data due to accidental deletion that is something relatively easy to take care. On most file systems when you delete a file it does not get deleted forever.
Data storing system in Windows
In windows even when you empty the recycle bin for example in windows the file system that marks file directories and entries as unused and it destroys the file allocation information except for the beginning of the file in NTFS only, which is responsible for storing and organizing files.
Data storing system in Linux and Unix
The file entry is marked as unused and the record is deleted from the directory and the disk space is then marked as free in most Linux or Unix file systems only the file descriptor is destroyed which is the information about the file location the file type the file size and so on marks the disk space as free so that new data can be written to it but as long as the data deleted do not get overwritten with any new data you can easily recover it using a file recovery program like Recuva .
As the data are still there but you can see it even though when you write or add something to your desk you may end up overwriting your important files since the old location is now marked as available and free this is why you must start the recovery process immediately after deleting your files.
How to recover formatted hard drive
If you accidentally format a hard drive which is a pretty easy mistake to make on a multi-drive system despite the scary message that windows will give you saying that all of the data is going to be destroyed when you format your drive essentially what happens is the data just gets compressed down and hidden from normal access the sectors on your hard drive are marked as available so that with normal use the drive appears to have all free space on it and new data can then be written to it.
So as long as new data doesn’t actually get written to the drive and our biggest enemy in this process is a de-fragmentation because it puts the file fragments back together moving information from one location to another on the same disc as it points to something that isn’t there anymore.
You have the right kind of recovery program you can get your data back hopefully completely intact whether you deleted it or whether you formatted the hard drive now these are easy software solutions to get around. If something more severe happens like corruption of the file system itself this typically occurs when the drive is suddenly disconnected during a read write operation like during a power outage it’s also common on a removable disk if you were to pull a flash drive out while files are still being transferred to it and that is why you typically want to eject your flash drive .

If you ever encounter a disk with a corrupted file system your computer will identify it as an unallocated space with no file system written to it at all but there is a file system here and there and data is corrupted so again you will use a data recovery program like Rstudio to scan the disk identifies what file system was in use and then pull the data off of it. If you already know the file system was in use you could skip that part and speed up the recovery process a bit.
What if a drive has a firmware problem?
If the firmware is the problem then it’s probably not something that you are going to be able to solve at home unless of course you happen to have one of these things because your operating system it is designed to work with a hard disk firmware that is well working on a normal PC. It is not going to be able to detect the drive when the firmware is corrupted, but the Rapidstar data recovery tool is designed to rectify some kind of firmware problem and so it can still read data off of a drive that has corrupted firmware.
What if your hard drive has a physical issue
If you start hearing the clicking and scratching and it probably can’t figure out where the data is supposed to start so it spins up attempting to read some data off of it and then it fails and then it starts up again in a continuous loop of failure if something like this were to occur you’re probably going to need some professional help.

The professionals would typically do to resolve an issue like this is to take the drive apart replace any components inside like the read write heads from a different or donor drives and then they would make a bit from bit copy of the data that’s on the dead drive onto a new one once it is readable again and then they can give the customer this new drive with all of their data intact on it .
Avoid fixing the drive yourself once unless you’re not a pro you start hearing that clicking and that scratching of doom the read write head on a drive sits just a few micrometers away from the spinning platter that’s a distance that is hundreds of times smaller than the thickness of a human hair. Drive must be disassembled in a clean room to prevent any dust from getting on it because even a speck between the platter and the reed right head could completely destroy a hard drive and these types of drive recovery where there is physical damage to the read write heads or the pcb or anything else like that are really the only ones that are worth paying for.
conclusion
Some of these kinds of data recovery are the ones that are going to be the more expensive it costs a lot to build a clean room and the skills that are required for this kind of recovery are very specialized but obviously it’s going to be worth it if the data that you lost is worth a lot of money to you so there’s few of situations in which you’re going to need professional help to recover data physical damage or corrupted firmware are the two main cases but just about any other problem can be solved with data recovery software.
The best solution to any kind of drive failure is to just have a backup so make sure that you do that before you lose your precious data.