I installed Recuva and tried to recover the deleted files . I saw some file names but when i opened the file, i saw data nothing. What is the use of the empty excel, word, ppt etc
Please advise
If you have securely deleted files the what was the data in the files gets overwritten, typically with zeros.
Once that is done then all any recovery software can find where those files used to be is all those zeros, ie, an empty file.
That is precisely why you use secure/permanant delete, so that there is no chance that the contents of the deleted files can later be recovered.
However the filenames themselves will remain in the Windows Master File Table, marked in that table as a deleted file.
Eventually they will be overwritten by new filenames as new files get created.
So you may still be able to see/recover the old filenames, but there is no data where those files used to be, only zeros.
In that case the recovery software (Recuva) can see from the MFT the filename and the location on disc where the start of the data for that file used to be,
It will recover everything it can from that location, but if it's been secure deleted then that's just a load of zeros, an empty file.