Data recovery problem. Please help me
 

I have formatted my harddisk fully & re-installed windows then is there any way to get the old data that i had in my hdd before formatting.

probably not without significant effort and expense search here
cheers:)

When you format a drive, you are generally just installing a file system infrastructure. This will overwrite some things and not others. Then, when you install an operating system (or anything else) you overwrite MORE stuff.

Thus---the answer to your question is: some, maybe.

Tools often recommended here are Photorec and Testdisk---I have used only the former.

What are the parameters: hard disk size, number and size of partitions, how much space is used by Windows, how much data was on there previously? etc. etc. etc.
(The more detail we have, the better the odds of helping.)

I'd highly recommend photorec

More details with screenshots here