Any problem encountered will find an easier solution if you understand it. For computer related issues, your solution might be in these pages. Here are some factors that might be causing the slow shut down process of your Windows Vista:

A corrupt or overflowing Windows registry. The registry is that part of your computer that is in charge of holding system related information on software and hardware. Some of these entries in the registry are unwanted and redundant. This is common for computers that have been long in use. Solution: Get a registry cleaner and clean your system.

A system page file in your virtual memory support is causing the delay. If "Clear Page file at Shutdown" has been enabled, this will take additional time for the computer to shut down. This is because the operating system has to wipe the system page file clean every time. Solution: disable the option.

You have recently installed a driver software or software application. Some of these drivers, services, and programs might be unresponsive and therefore causing the slow shutdowns. Try to recall if the problem started right after the computer underwent an installation. Solution: Use System Restore. This will roll back or take back your computer system to its previous pre-installation state. Other actions that could be performed to speed up the shut down of your Windows Vista are for your computer system to undergo the clean boot troubleshooting procedure, disabling something called "Terminal Services" which is found in the Control Panel of your PC, closing any and all the applications before a shutdown.

Researching your options before performing any of these suggested actions is a must. Chances are you will come across more detailed instructions on the procedures that are being discussed here. The Windows help page on the net is a logical source of information. There are sure to be other links as well.