Using SQL Server Management Studio
To configure the user connections option
1.In Object Explorer, right-click a server and click Properties.
2.Click the Connections node.
3.Under Connections, in the Max number of concurrent connections box, type or select a value from 0 through 32767 to set the maximum number of users that are allowed to connect simultaneously to the instance of SQL Server.
4.Restart SQL Server.
sql server 最大 concurrent connection 设置
原文：http://www.cnblogs.com/lthxk-yl/p/6862154.html