>Determining if a Drive letter is already assigned isn't the problem. What I'm trying to accomplish is to make certain that the share as typed exists like \\mike-win2k. I add the c$ share when I actually assign a drive letter. I know that if the "communication server" is not turned on, the share won't exist, but that is a problem for our customer support. I could just let the user type some text and fail at the point I try to connect, but I'd prefer not to do that.
>
Why not use WNetAddConnection3() to try logging into the drive without mapping it? Download my NETRESOURCE and CLSHEAP classes - there's sample code for WNetAddConnection3() in NETRESOURCE.