I'm confused - is the query that you killed the query that you were using to do index maintenance? And that was running for 4 days before you killed it? Or it was the query from your web server that was running for 4 days before you killed it?

I always hesitate in restarting SQL Server. Always a last resort. If it was the query from your web server that was running for 4 days before you killed it, do you have any idea what it was doing? Query text? If it was an update, insert, or delete, you may need to wait as long as 4 days (sometimes more) for the query to completely rollback.