OK, this seems to be an issue regard the service pack level of your Workstation. This problem can occur if Windows NT is installed and the latest service pack is installed before any network services are installed. If the Srv.sys file is not present when the service pack is applied it is not updated because Update.exe updates only components that are installed on the Windows NT system. When Windows NT starts up after the network services have been installed from the original Windows NT CD-ROM, the original non-Service Pack 3 version of the Srv.sys file is used. To correctly work with the rest of the updated system files, the Srv.sys file must be updated to the same version as the installed service pack. Otherwise re-apply service pack 3 for NT Workstation. (Microsoft Article Q151427)