suppose u want to hide a folder named "hello"which is in D: of ur computer

go to command prompt
start--->run--->cmd-->d:


after changing it from C: to D:

type D:/>attrib +h +s hello
the above command is to hide the folder

to show the folder

type D:/>attrib -h -s abc

in this type of hidding the folder cannot be viewed even if we make advance search or even changing the folders menu to (show all hidden files) !!