Check name fails 2008r2

In aduc I created a domain local security group in the users container. The group name is servicedocsro . Opened start – computer and double clicked drive C. Created a folder named service docs. I need to share the folder, given permissions as follows: Give the servicedocsro group read. When I try to share the folder service docs and try to do a check name it gives me name not found. What am I doing wrong?