如何判断SQL Server已启动并可以使用？

I have an app that runs on system startup that needs to talk to the local SQL Server 2005 installation. I'm using the ServiceController class to wait for it to enter the "Running" state, and most times this works fine. However, sometimes on a cold boot, my first query fails, saying that it couldn't log on the current user.I have an app that runs on system startup that