Here is my Device update script that forces the computer to be
restarted and then delete a file after the computer restarts.

// Reboot
REBOOT,,DAREBOOTOPT_REBOOT

// Delete a file
DELETEFILE,,,D:\CABLETEST\File_old.exe

First, the above command could only shutdown my system, not restart.
Do I have to set other system settings in order to allow the computer
to restart?

Second, the delete command after the restart doesn't work. It never
able to delete a file even that file exists. I have checked the event
viewer log and there is no log entries about the execution of the
device update script after the computer restarts.

This example is very similar to the example provided on Microsoft
website in deleting system files. Any one has any idea why it doesn't
work in my system?