在服务器上登录过数据库信息，并且选择了记住了密码，由于服务器数据库很多人在使用，有必要删除信息
定位到fileC:\Users\%username%\AppData\Roaming\Microsoft\Microsoft SQL Server\100\Tools\Shell\SqlStudio.bin，确保已经关闭SQL Server ，把SqlStudio.bin删除掉，再重新打开就完全清除数据库地址、登录名和密码。
SQL Server Management Studio 2017 delete the file C:\Users\%username%\AppData\Roaming\Microsoft\SQL Server Management Studio\14.0\SqlStudio.bin
SQL Server Management Studio 2016 delete the file C:\Users\%username%\AppData\Roaming\Microsoft\SQL Server Management Studio\13.0\SqlStudio.bin
SQL Server Management Studio 2014 delete the file C:\Users\%username%\AppData\Roaming\Microsoft\SQL Server Management Studio\12.0\SqlStudio.bin
SQL Server Management Studio 2012 delete the file C:\Users\%username%\AppData\Roaming\Microsoft\SQL Server Management Studio\11.0\SqlStudio.bin
SQL Server Management Studio 2008 delete the fileC:\Users\%username%\AppData\Roaming\Microsoft\Microsoft SQL Server\100\Tools\Shell\SqlStudio.bin
SQL Server Management Studio 2005 delete the file – same as above answer but the Vista path. C:\Users\%username%\AppData\Roaming\Microsoft\Microsoft SQL Server\90\Tools\Shell\mru.dat
参考：
How to remove cached server names from the Connect to Server dialog
Removing the remembered login and password list in SQL Server Management Studio