Recently after updating the antivirus solution at one of my customer sites they started receiving the following error when attempting to access their old Windows 2003 servers: "\Server\Share is not accessible. You might not have permission to use this network resource. Contact the administrator of this server to find out if you have access permissions. Not enough server storage is available to process this command." The solution was to increase the IRPStackSize on the remote server as referenced in this Microsoft Support article.