My windows 7 is stuck in shutting down when shutting down

Adding some things you can also try
Something is not being released by windows,
when you click shutdown do you see any programs still open on the display like windows is waiting for xx program to close?
Check your task manager prior and close all folders remove USB drive if still there with safely remove, disconnect USB printer.
Try removing the shutdown windows sound if you have that enabled.
rightclick the speaker icon on the task bar then open sounds, scroll down to>Exit windows.
highlight and then untick play windows start-up sounds,
in the panel below scroll the sounds to the top None. Apply.
If this fixes it then your windows sounds may be corrupted.
Run a system file checker.
Are you on a Domain?
Please also try the following steps.
Go to Start, type Group Policy in the Search Box and then click Edit group policy.
Expand the following item from the left pane:
Computer Configuration -> Administrative Templates -> System -> Logon
Double click "Always wait for network at computer startup and logon" setting on the right pane, choose Disable and then click OK.
Exit Group Policy Editor and check the result.

Try this one as well from Microsoft relates to a changed registry key after installing sp1
 and ensure that the value ClearPageFileAtShutdown is set to 0 (if it is set to 1, change the value to 0).
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management
http://social.technet.microsoft.com/Forums/en-US/w7itproperf/thread/9b3ff136-8a71-444b-bb80-2973ff838693

the following steps are for windows xp, but valid for windows 7

Open REGEDIT. Click on Start/ Run and type ''regedit'' without quotes and click ''OK''... Navigate to 'HKEY_CURRENT_USER\Control Panel\Desktop\'
Highlight the 'WaitToKillAppTimeout' value.
Set it to '1000' (the default should be 20000).
Now highlight the 'HungAppTimeout' value
Set it to '1000' also.

The second part of this tip changes the same settings, this time for all users on the system.

Navigate to 'HKEY_USERS\.DEFAULT\Control Panel\Desktop'
Highlight the 'WaitToKillAppTimeout' value.
Set it to '1000' (the default should be 20000).
Now highlight the 'HungAppTimeout' value.
Set it to '1000' also.

In the third part of this tip, we will alter a second registry setting to decrease the amount of time Windows XP will wait before shutting down active services after receiving a shut down command.

Open REGEDIT and navigate to 'HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\'

Highlight the value 'WaitToKillServiceTimeout'

Change this value to '1000.'

This should help to considerably speed up the time windows XP takes to shut itself down

Auto kill tasks on shutdown

To allow Windows XP to close non-responsive applications automatically upon shutdown:

Open REGEDIT and navigate to 'HKEY_CURRENT_USER\Control Panel\Desktop'

Highlight the value 'AutoEndTasks.'
Change the value to '1'

Also 'HKEY_USERS\.DEFAULT\Control Panel\Desktop'

Highlight the value 'AutoEndTasks.'
Change the value to '1'

There is a possibility the windows is installing the windows update while shutting down too, have a check windows update setting from here : Start > Setting > Control Panel > select "Windows Update" > try to select the option "Download the update but let me choose whether to install them" , see whether it help.

is your problem recent?  then a system restore is a quick way out

Great! thanks a lot