I want to run a query from Enterprise Manager, but it times out at 30 seconds, generating the following message:

<i>SQL Server Enterprise Manager
\[Microsoft\]\[ODBC SQL Server Driver\]
Timeout expired</i>

I've tried to change the Query timeout option from the Tools, Options, Advanced dialog box, but the option doesn't have any effect. How can I get my query running?

I assume you're trying to run a query that you created through the Graphical Query Designer, available from the Query option on the Open Table menu within Enterprise Manager. Unfortunately, the timeout is hard-coded to 30 seconds for queries running from that interface, and you can't override the default timeout value. You can still use the Graphical Query Designer to build the query if you aren't comfortable with T-SQL, then simply copy the query into Query Analyzer to run it. You can control the query timeout setting in Query Analyzer's Options menu.