og her lidt mere:
If it appears that Win XP is not shutting down, give it some time. Some users report a minute or longer for shutdown to visibly start. Generally, this is a consequence of software that is running when shutdown is attempted. It also may have something to do with particular hardware. If you experience this problem, be sure to close all running programs before attempting shutdown and see if this solves your problem. If so, then you can determine, by trial and error, which program(s) are involved.
Correspondent Graeme J.W. Smith reported a more obscure cause of slow shutdown: In Win XP Professional, the Group Policy Editor has a security option to clear the pagefile at system shutdown. The same setting also forces the hibernation file to be wiped at shutdown. These processes take long enough that users may think that shutdown has hung. To change the setting, click Start | Run, type GPEDIT.MSC, click OK. Drill down to Computer Configuration | Windows Settings | Security Settings | Local Policies | Security Options. In the right pane, find “Shutdown: Clear virtual memory pagefile.” NOTE: Since someone actually has to have set this policy, the problem will be pretty rare, but is worth mentioning. However, Forum participant “roadrunner” reported that the personal security app Privacy Eraser automatically enables “Clear virtual memory pagefile,” and, therefore, may be the cause of a slow shutdown.
MS-MVP Gary Thorn discovered that the Event Log can slow down Win XP shutdown. Disabling event logging removed the slowdown. If this works for you, then the real troubleshooting begins: finding out, by trial and error, what item that is being logged is causing the actual slowdown. (In Gary’s case, the Telephony service was causing the problem.) To disable the Event Log, launch the Services console as detailed in No. 2 above, and disable Event Log (right-click on Event Log, click Properties, under Startup Type select “Disabled”).
http://aumha.org/win5/a/shtdwnxp.php