Thanks for the response. The application is more general. It is part of a security program that uses a very large randomly generated key file to x-or with already encrypted files. the program itself will use a mapped network drive to supply the key file to the encryption program, and the program will present the network drive id to the user, but in a randomized fashion, so typing (or clicking on) "3" for instance, does not always mean drive "D:", nor would the exact share be available in the MRU List. The encryption program has some other features, but the shear size of the key file and the fact that it is randomly generated gives just one more level of security for confidential data. The intent is to hide the tracks of where the encryption key came from, since having it on a local drive is not as secure.