Synchronization ERROR

Hi Sir

I have a problem in Synchronization, when I tried to use or select the Synchronize All in NAV SQL OPTION… my Login is deleted in SQL SERVER. So when I tried to login in again unsing window Authencation, ERROR Msg Apear say Invlid ID and USERNAME. What do you think is the problem?Please give me advise on how to fix this.
I hope you can help me.THANKS

I assume you are referring to a Windows authenticated login.

Is your login present in the table, under Tools/Security/Windows Logins?

The Login is just Setup in SQL SERVER and have not Add it to Windows Login. So,I have to add the login in Windows login in NAV?TY

Yes you have to add the logins to NAV and assign the permissions here also.