I had a share that was setup with permission for Domain Users on a windows server 2008. Everyone could access it. We wanted to allow only certain users to access the folder. I removed the "domain users" from the list and added the individual users, about 80 of them, this worked for almost everyone. there are 3 users, who have contributor rights, that can not open the network share. I ve tried promoting them to co owners and still it doesn't work.