error while inserting the users in NAV

I am trying to insert a windows login in NAV but it throws this problem. can any one help me

Did you try to synchronize all users before inserting?

Yes i have synchronised the users before inserting this user in NAV… but still pops the same error.

Check in SQL Server, Databases, Under your database Security, Login

Whether you have the user or not.

Yes i do have the user in the sql server as well…!!

Please delete the use from SQL Server Master Database and add from NAV

I have tried to delete the user from the active directory and also from sql server but i am facing the problem to drop the user although i have admin rights. How can i do that ? can u give me some guidelines??

Remove the user for SQL Database first and then try to add in Navision and do synchronize.

Thanks for the replies… i have solved the problem by deleting the users from the SQL .