I'm currently developing a new ASP.net project hosted on a Windows Server 2008 RC2 with an MSSQL 2008 Express Database. I have three SQL instances (for different purposes) running which currently all contain a single database.

For apprently no reason, these instances tend to shut down after some days, for no apparent reason. There might be low or none traffic to these instances, because there might be some days in a row, where I can't develop.

It now occured several times, that one or two of these three instances just shut down, so that I can't access the database, without manually starting the instance.

I can't seem to find a event log entry for the shutdown, which is most likely because I just enabled logging (why is the default setting off?)

So the questions are: * Why does a SQL instance shut down? (Is there such thing as a "Shut down instance after 3 days of inactivity"? * How can I achieve that the instances are running 24/7?