T-SQL: Quickly Kick All Users Out of a SQL Server Database
There are a few ways to do this but here's one that I like. I believe it works in SQL Server 7, 2000 and 2005.
ALTER DATABASE myDatabaseName SET SINGLE_USER WITH ROLLBACK IMMEDIATE GO USE myDatabaseName GO
Go ahead and do what you need to do then set it back:
ALTER DATABASE myDatabaseName SET MULTI_USER