Question: Is it true that when you delete files they can still be found on your hard drive and if so how do I find them?
Answer: Deleting a file just changes the first character in the directory to mark the file as deleted. The rest of the directory entry and the file itself are still there but can now be overwritten piecemeal by any subsequent writes to the disk. You need special software that reads the drive content directly rather than via the operating system to be able to see and recover deleted files. Of course if subsequent writes to other files have been done then part of the file may have already been overwritten.
This article written by Stephen Chapman, Felgall Pty Ltd.