How to delete recent connection from Connect to Server window in SSMS is a very common issue and it becomes frustrated if you connect many servers on daily basis and SQL Server Management Studio (SSMS) pile up all the new server names in the list of Connect to Server window as shown below.
I have been facing this common problem since SQL Server 2005 and it has been reported on Connect as well. Fortunately we do have a solution explained in this article that demonstrate step by step how to delete the recent connection list using mru.dat and SqlStudio.bin in SQL Server 2005 and SQL Server 2008 respectively. However, this is NOT smart solutions because it deletes all your recent connections including the active ones as well.
In SQL Server 2012, a proper solution came in the picture and I believe, this is much better than the earlier solution. Let me demonstrate it step by step.
Step 1 :
In order to open “Connect to Server” window, first of all you need to select file menu and click on connect object explorer.. in SSMS as shown below.
Step 2 :
Once you open the Connect to Server window, you will find all recent connections in the server name as shown below but the drawback is you cannot determine what belongs to SQL Authentication and what to Windows.
Step 3 :
Now, you need to eliminate the connection. In order to do it, you need to select the particular connection and press DELETE button from the keyboard. Once you press delete button, it will delete that particular connection but it will remain as selected in the server name dropdown list as shown below. If you need to delete multiple connections, you need to select server one by one and press delete button to delete it, as multiple selection is NOT allowed.
Let me know if you come across this scenario and how did you resolve it.
SQL Server Portal 