slow
sounds like either a cluttered registry or too many unwanted or heavy resource processes running. Have a look at the clean pc post and note the registry cleaner and procexp utilities.
Have procexp open while the pc is shutting down, while its taking its time, use a binary method (one at a time) for finding out if a particular app is slowing the shutdown process by killing the apps from procexp to see if that speeds it up.
Ive experienced this with running a number of resource hungryservices on my laptop, that when shut down properly, speeded up the shutdown process.
failing that and not knowing your OS, is there anything useful