HKEY_USERS\.DEFAULT\Control Panel\Desktop, Value Name: AutoEndTasks, Data Type: REG_SZ (String Value), Value Data: (0 = disabled, 1 = enabled). Modify the value of 'AutoEndTasks' to equal '1' to automatically end tasks or '0' to prompt for action. Note: This change will affect all users but the value can also be changed on a user-by-user basis by modifying [HKEY_CURRENT_USER\Control Panel\Desktop] with the same values. Will take care of the Not Responding Apps on shut down, but I highly suggest you DO NOT use it, unless you know what you are doin', if you want, you can backup your registry before and attempt it, NO MATTER WHAT! Always back up the registry before editing.
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Contro l. On the Edit menu, click Add Value. Value Name: WaitToKillServiceTimeout, Data Type: REG_SZ , String: In milli-seconds; default is 20,000. Ok/Exit/Reboot. This will also speed up the time for services to close PROPERLY before shut down.
These were found on http://www.kellys-korner-xp.com/xp_reg_edits.htm