You will experience the subject behavior if the local Administrator account on the computer that is running the Remote Desktop Sharing (RDS) service has a blank or null password.
To resolve this issue, set a password for the local Administrator account on the computer that is running the RDS service:
1. Open a CMD.EXE window on your computer.
2. Using CryptPwd.exe, type:
CryptPwd -u Administrator -m \\RDSComputer -P NewPassword
RDSComputer is the computer that is running the RDS service. NewPassword is the password that you wish to set.NOTE: -P must be capitalized.
3. Restart NetMeeting.
4. When prompted for credentials, type Administrator and the NewPassword.