Vista - Cant See A Particular Folder in Drive D - do not have any folder made invisible

Hi,

I thought i lost a folder (accidentally erased it) in drive D,but when i
tried to replace that folder and its contents by copying and pasting,I keep
getting a message asking me if i want to replace that folder.The folder
seems to be invisible in drive D and it also doesnt come up from a Search,it
only shows that folder is on drive when when i try to copy and paste the
same folder to drive D or i try to create another fold in drive D with the
same name.

What happened top this folder??
I use Folder Lock,but i doubt that is what caused it.

Anyone know how to fix this?

Thanks