When you try to install an instance of Microsoft SQL Server 2005 on a computer that has an instance of Microsoft SQL Server 2008 already installed, you may receive the following error message:
An instance with the same name is already installed on this computer. To proceed with SQL Server Setup, provide a unique instance name.
This problem may occur if one of the following conditions is true:
- The existing instance of SQL Server 2008 is a unique named instance. However, you try to install SQL Server 2005 as the default instance.
- The existing instance of SQL Server 2008 is a named instance, and you use the same name when you try to install SQL Server 2005 as a named instance.
To work around this problem, use a unique name when you install SQL Server 2005 as a named instance.
Article ID: 955500 - Last Review: Mar 19, 2009 - Revision: 1