Can't troubleshoot that query without more details on it.
One specific thing to check, though, is that you have limited SQL's use of RAM via the 'max memory' setting, and not left it at the default of unlimited. Performance can become horrible if SQL uses so much memory that you get into memory thrashing between SQL and Windows.
SQL DBA,SQL Server MVP(07, 08, 09) "It's a dog-eat-dog world, and I'm wearing Milk-Bone underwear." "Norm", on "Cheers". Also from "Cheers", from "Carla": "You need to know 3 things about Tortelli men: Tortelli men draw women like flies; Tortelli men treat women like flies; Tortelli men's brains are in their flies".