scchedule a windows 2000 server shutdown

i would like to set up a scheduled routine whereby my w2k file server is shutdown at 7.30.p.m. every evenning. i used the built in windows scheduler service & specified a predifined batch file which includes the following line:

@echo off shut down /L/A/Y/C

i specified the required time to run the task.
But i it just gone log off instead of shutdown & power off the server.

why? any one can help me ?

regards,

bctan