On more than one occassion I've hit a problem where the mapped network drives got messed up, both under the hood and in Explorer on a Windows Vista machine. I couldn't completely disconnect drives, Explorer thought they still existed but they didn't, and references to network locations existed when checking with "net use" but weren't mapped to any drives when looking, so couldn't be remapped. Dealing with the network locations with no mapped drive was probably the easiest to resolve. net use ( more info on net use ) using this from the command line showed info about the network resources. To remove the network connections with no local drive just use: net use \\servername\folder /delete To delete a local resource use: net use S: /delete Sorting out the problem with Windows thinking that connections still existed, but didn't actually exist was a little trickier and involved getting in to the registry. Steps involved were: Opening the