Hello,
I'm not very experiensed with dcm4che-arc , but I could suggest you check the following:
1. Make sure that openldap's port (default is 389) is not used by any other program or service (Open command prompt and type netstat-ano-p tcp to check ports being used)
2. Is your slapd.conf file in LDAP installation directory configured properly? (See attachment Capture1.png for details)
3. I once had the same problem , so I changed Database backend to MDB during installation of OPENLDAP. Then , service worked properly and stopped hanging.
Hope I helped!