What system file are you using? FAT or NTFS?
It's like your folder is there but is not listed in the index, you shuld try to search for a program that looks to your HDD without using windows' explorer.
I suggest to look for an undelete program that works on NTFS file system, your folder it's probably still there, just DONT'T WRITE ANYTHING ON YOUR HDD because it may overwrite some files.
If some recovery programs find your files it will "save" them on another disk.
Try searching some programs around the net and do some tries.