How do I know how many instances SQL Server?

How many instances is my server installed?

Here is a simple method: go to Start then Programs then Microsoft SQL Server 2005 then Configuration Tools then SQL Server Configuration Manager then SQL Server 2005 Network Configuration then Here you can locate all the instance installed onto your machine.

How many instances can a SQL Server have?

You can install as many as 50 SQL Server instances on a Windows Server; obviously, we do not recommend this. In a Windows failover cluster, the maximum number of SQL Server instances is reduced by half if you're using shared cluster drives. Only one of the SQL Server instances on a server can be the default instance.

How do I know if SQL Server instance is installed?

Using SQL Server Configuration Manager Click Start, point to All Programs, point to Microsoft SQL Server, point to Configuration Tools, and then click SQL Server Configuration Manager. If you do not have these entries on the Start menu, SQL Server is not correctly installed.

Can a SQL Server have multiple instances?

Yes, we can use multiple instance of SQL Server of same machine/server. All instances of the database engine other than the default instance are identified by an instance name specified during installation of the instance.