We have been using Windows 2000 to support our network of 9 computers running Windows 7 for many years with no restrictions on access to files on our server. Recently we have been getting what is marked as a Windows Security request for a user name and a password. We did not install such a restriction and do not know how or why it was installed. Since we did not install this restriction, we do know know what user name and password is required, so none of the computers can access the files in the server. Has anyone else encountered this situation, and, if so, how has it been dealt with. Any help would be greatly appreciated. Thanks.