Recovered some files, not all - newbie needs help!

I stupidly deleted a folder that held 48 videos, all about 700MB - 1.1G in size. I ran Recuva and was able to get 35 files back. What happened to the rest? If I run it again it just "finds" the same 35 files.

Super desperate here!! These files are my student's video interviews for a high-stakes assessment which we just spent the last 4 days making and I'm freaking out.

Unfortunately this is how Windows works. Assuming you're running a Recuva normal scan on an NTFS hard disk:

File information, such as name, cluster addresses etc, is held in records in the Master File Table. When a file is deleted these records become available for reuse and new file creation can overwrite the old information. So Recuva will only be able to find the records, and the files, that have not been overwritten. It's probable that some of your deleted files' records have been overwritten.

The lost files' data is quite possibly still in existance on the disk. You could run a deep scan and there's a good chance you will find the lost files, along with many thousands of others. They may not have the original file name, as that was held in the MFT, so you will have to identify them by size or date, or inspired guess.

The bad news is that large files are likley to be fragmented, and deep scan will only find the first fragment, as there is nothing in subsequent fragments to identify them. But you have to try.

I trust you have recovered the 35 files already found, as every use of your pc runs the risk of reusing the MFT records for those files, as indeed using your pc runs the risk of overwriting your lost files' data.