That is, to have a chance at recovery you stop using this drive. My best efforts pull the HDD into some USB case for use on another PC then see if we can find it with RECUVA (this and other apps are noted at http://www.cnet.com/forums/discussions/lost-and-found-or-the-storage-forum-sticky-354911/ )
The reason we must never use the drive is that use can overwrite what was lost. If the apps can find them then we call DRIVESAVERS.com and see if they can find it.
It's just one folder, important stuff so why no backup copies? With all the free storage online like Dropbox and others, we can make our files hard to kill.
It's very urgent, yesterday my laptop suddenly shut down and never restart again then I go to shop and repair my laptop but I lost my very important file and images which was stored in a folder but I doesn't find that folder yet.