If you happen to be using SQL Management Studio in Windows 7 and need to connect to a SQL 2005 instance not running on the standard port of 1433, you might be having some problems connecting. For some reason this mix seems to require the SQL port to be manually defined when connecting to any named instance.
The fix is to specify the port in the server name used in the Connection prompt. So if your SQL instance was called SQL02 and running on port 3433, you’d use “MySql2005Server,3433 SQL02”.
If you don’t know the port that SQL server is running on (maybe you have an external vendor supporting SQL), you can connect to the server from a Windows XP machine and run,
netstat -a | find /i "mysqlserver"
This will show you the network connection from your machine to the SQL server and the port being used.