In Active Directory Users and Computers (ADUC) properties window is slow to come up after installing Authentication Services
Microsofts .NET framework attempts to connect to check for revoked security certificates. If the workstation has no internet access this can create a delay of upto 15 seconds.
Disable Certificate Revocation Checking (CRL) Checking, by doing the following:
1 - Go to Control Panel | Internet Options | Advanced | Under security
2 - uncheck the "Check for publisher's certificate revocation option"