POWERTOY的AUTO LOGIN也許是最好的方法...
ANYWAY..我還找到了一個奇怪的答案from KELLYS KORNERS 的xp 網站
http://www.kellys-korner-xp.com/xp_s.htm

Scheduled Tasks- AutoRun

Q. What is the secret to getting tasks to run when no one is logged on when using Windows XP?

-schedule service is running, set to automatic, log on as 'local system'
-task is scheduled to run under an user account which is an administrator
-task is scheduled to run under an user account with a password
-task itself is legit as it will run when executed directly
-task schedule setup is valid as it will run IF I remain logged on
-Event log shows nothing
-task log shows no attempt to run the task
-task status is 0x0, but that is irrelevant since 'time last run' reveals it was not run at all

Since schedule runs as a service with startup set to automatic and logon set to 'local system', one would
assume that schedule service begins running when the computer is started, regardless of whether or not anyone
logs on. Since the task is set up to run with an administrator logon complete with password, one would assume that since the schedule service is running, at the scheduled time it would logon as the designated user and run the task.

A. You need to replace the Task Scheduler Log File which can be accomplished quite easily. If you follow these
exact instructions, the shedlgu.txt file will be replaced with a brand new one without any information other than
system start-up information upon the first boot. Click Start>Click Run> and type msconfig> click Selective
Startup and uncheck the Load System Services check box. Click OK and wait for the hour glass to stop. Restart
the computer, click OK to the first Window that indicates that you have selected "Selective Startup".

When the System Configuration Utility reappears, Check the Normal Startup Box. Click Start> Click Search> Click All Files and Folders Category and type schedlgu.txt and Enter. Windows will search and locate the schedlgu.txt file. Press Stop
as soon as the file is located. Right click on the file schedlgu.txt and delete and send to the recycle bin. Now restart the computer again by selecting Start>Turn Off Computer and Select Restart.

You will now have a new Task Scheduler Log File. You may check the new Log File and the one start up entry that I described by selecting Run and typing the file name schedlgu.txt and click OK. Appearing will be your new Task Scheduler Log.