Folder securiy issue after adding old server to domain

Another problem has arisen from adding this clinic to our network. Their old DC that I dcpromo'd and removed AD DS, DHCP and DNS roles from I think is somehow impacting my existing domains file and folder shares. somehow the security on my "users" drive has been modified. there are still file services running on the now old member server could this be the culprit? Its not a Domain controller its should just be a member server so I ASSumed that there would be no replication of any kind going on? HELP!