SQL Server: 2005 instance running, need 2008 instance to run instead

I hav开发者_开发问答e both SQL Server 2005 and 2008 installed on my machine. Only the 2005 instance is being detected as running (via Windows apps, like Management Studio and LightSwitch). How do I change the running instance to the 2008 version?

Sounds like your default instance is 2005. Your 2008 instance must be named instance:

http://msdn.microsoft.com/en-us/library/ms143531.aspx

You can connect to a named instance using the server\instance notation

http://www.compiledthoughts.com/2009/04/understanding-ms-sql-server-named.html