When stand-alone WSS is installed on a machine which doesn’t have SQL 2005 standard edition or higher installed, the setup installs a special embedded edition of SQL Server with an instance name Microsoft##SSEE. By default settings this SQL server is not exposed to outside world and you will not be able to connect to it from management studio. But there might be situations which require connecting to this embedded SQL server. Following steps explains this process
1.       Open SQL Configuration Manager from Programs -> Microsoft SQL Server 2005 -> Configuration Tools.
2.       Expand the SQL Server 2005 Network Configuration node.
3.       Right click on Protocols for the Microsoft##SSEE instance and select properties.
4.       From the properties window that shows up select HideInstance property and change its value to No.
5.       Click OK to close the properties window.
6.       Restart the embedded Microsoft##SSEE  SQL server instance using Surface Area Configuration Tool.
7.       Now you will be able to connect to the WSS embedded Microsoft##SSEE  SQL server instance from SQL server management studio using windows authentication.