There'll be a reason why your tempdb is that big - perhaps, rather than shrinking it immediately, it would be better to figure out what that reason is. It may well be that the reason it's that big is that's the size it needs to be. So. Why is tempdb the size it is? Do you have a long-running transaction building a big temporary table there? Do you have some big indexes that get rebuilt in TempDB? Do you have other processes / applications creating normal tables in TempDB and not tidying up after themselves?