I setup a couple of Windows computers on my home LAN, then renamed the network (workgroup) to which they belonged. The problem is that both names show up on my Mac's Network directory, and I can't delete the old name. When I try to drag it to the trash I get an unexpected error code of -61. I also tried the terminal commands 'sudo rmdir old-network-name' and also 'sudo chmod 755 old-network-name' but got the error message that it was a Read-only file system for both commands. How can I remove these folders?