Whenever you login into database server through management studio the server name and username gets saved automatically. Management studio does this for future DBA's/Developer's/Programmer's logging in reference .
The screenshots below shows how sql server management studio saves database info :-
Now you might require to delete the saved credentials.
To delete the Credentials :
- Go to the file location in the Windows 7 system's hard drive :-
C:\Users\pablo *\AppData\Roaming\Microsoft\Microsoft SQL Server\100\Tools\Shell
Note :- (*) is subject to change according to the login name by which you logged into windows.
- The directory should contain a file named as SqlStudio.bin
- Delete the file and you having successfully removed the Saved Server names and usernames from your SQL Server Management Studio.