Hi pramosha,
Photorec is a nice software to extract files by file type, but be aware that it won't restore the file names.
You must be aware that you need a second hard drive, with sufficient capacity to output all the files that were on the drive that you partially accidentally formatted.
For instance if your 2 TB drive was 40% full, you will need a 1 TB drive to output the files.
NEVER restore the files to the same drive !
If the data are important, I would suggest you contacting a data recovery professionnal, which is not a common computer shop, but someone who is specialized in data recovery.
I'm not telling that you won't success in recovering the files by yourself, but as a newbie the chance of doing irreparable mistakes is quite high.
A data recovery professional won't run any data recovery software directly on your drive but on a clone. So, additionally to the first mentioned "output drive", you'll need for this clone, a drive of 2 TB or more. And at this step, for a newbie, the risk of making unrecoverable errors is quite high too.
For the kind of data lost you encounter, the data recovery by a profesionnal should not be very expensive if your drive is good physical condition.
Cloning your drive can last about a full day as it is quite large.
Only then, the scan for lost files can be started.
For a deep scan, the total data recovery duration should be about a small week (office hours).
You should consider this:
- If your drives (source & target) are not connected via high-speed interfaces,
the recovery process will last about 5 times the one I describe above.
Maybe is your drive USB 3, but if your PC USB sockets are USB 2, then it will work as USB 2.
- Powerful data recovery softwares are often paid softwares.
(Photorec can recover a lot of file types, but maybe you are also enjoy if there is some possibility to preserve your folder structure and file names.)
- Data recovery specialists use temporary storage to secure your data before the scan/analysis. (The clone drive I mentioned above.) This is one more thing that you'll have to acquire if you want to do the recovery by yourself.
- Data recovery of a drive like yours (2TB) takes lot of time. A professional data recovery costs, but you can "invest" your time is something else that doing the recovery by yourself.
That said, if you want to do things by yourself, Photorec has a "Step by Step" guide that you can find here :
http://www.cgsecurity.org/wiki/PhotoRec_Step_By_StepRegards