How can I detach a database that is in use?
Solution 1:
--Kick all users off of the database NOW
ALTER DATABASE YourDatabase SET SINGLE_USER WITH ROLLBACK IMMEDIATE
--Kick all but after 60 seconds
ALTER DATABASE YourDatabase SET SINGLE_USER WITH ROLLBACK AFTER 60 SECONDS
--restore connection to users
ALTER DATABASE YourDatabase SET MULTI_USER
Solution 2:
Have you tried checking the "Drop Connections" box when you detach it?