To configure the default option in the Windows XP shutdown dialog box to be "Shutdown", configure the following registry value:
Key: HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer
Value: Shutdown Setting
Type: REG_DWORD
Radix: Hex
Data: 00000002
----------
Possible values for Shutdown Setting:
00000001 = Log Off
00000002 = Shut Down
00000004 = Restart
00000010 = Stand By
00000020 = Stand By (with wakeup events disabled)
00000040 = Hibernate
00000080 = Disconnect (only available in Terminal Services sessions)
Don't forget to commit the change to the image when done or it will come back up with the original setting again.