Their may have been times that you would have liked your desktop or laptop to shutdown faster so that you could pack it up and move.
But it just does not shutdown so fast-Here is a windows(not for windows 7) tip that will certainly help you in achieving faster shutdown speeds.

Go to the start menu and then open the run program
For vista press windows button+r to open the run .

Type “regedit” in the run box and hit ok

type regedit without any spaces

Your registry will open up.

On the right side of the window go to HKEY_LOCAL_MACHINE

You will see a drop down-click on the SYSTEM and then current control set

HKEY_LOCAL_MACHINE->system->currentcontrolset

Now on the left side of the window you will see WaitToKillServiceTimeout

Change the data options to around 1000 0r below.

Adjust the killouttime according to your needs

Remember this is a tweak and it may(may) harm your machine so its advisable to make backup of your registry

In case your computer does not boot up,restart your machine in safe macine in safe mode and slect the restore point that you had just created.

If you are using linux then you may want to have faster boot-up and faster shutdown speeds-Decrease boot time in linux