SQL Connection Error 10053 : Event ID:17809 - Solution

Error Message : 
A connection was successfully established with the server, but then an error occurred during the login process. (provider: TCP Provider, error: 0 - An established connection was aborted by the software in your host machine.) (Microsoft SQL Server, Error: 10053) For help, click: http://go.microsoft.com/fwlink?ProdName=Microsoft+SQL+Server&EvtSrc=MSSQLServer&EvtID=10053&LinkId=20476

Event Log : 

Could not connect because the maximum number of '2' user connections has already been reached. The system administrator can use sp_configure to increase the maximum value. The connection has been closed. [CLIENT: 192.168.8.74]

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.

First go to services and stop Service named SQL Server (MSSQLSERVER) Now Start both SQL Server (MSSQLSERVER) and SQL Server Agent (MSSQLSERVER)
Now you can connect to your database

Or you can increase the number of connections using sp_configure

see this article : http://msdn.microsoft.com/en-us/library/aa259616%28SQL.80%29.aspx