sureshkm :
Thanks @GshislainG.. Actually i deleted them permanently but before that i copied them to flash drive which i lost. I am too much scared as it contains my family photographs. After every family event i create a folder of that event & put all related photographs in it. I have transferred some of the folders in flash drive. I just want to know the names of that folders. Any help would be appreciated..
Unless your computer is psychic, it's impossible (and no sentient psychic computers anywhere in the world right now).
What you need to do is search for the drive in your home, car, other places you might have lost it in.
Wherether or not you find the drive, it's time to rethink how you store important documents. The best method is to have multiple backups, one in the computer, one on removable media, and then an archive copy on DVDs or another HDD that you lock away in a safe somewhere. You should also consider online storage, something like Smugmug is dirt cheap and backed up several times to make sure that data never disappears.