Windows Scheduled task failed to start

The recent backup script that runs on Windows Server 2003, after July 23, is no longer running, and the status you see in the scheduled task is: failed to start.
Results manually run a backup script, no problem, can run normally, but in the planning task why not, and then want to look at the log of the scheduled task, but do not know where the log, some say is:

SCHEDLGU.TXT, then in the c drive, searched again, did not find, someone said look at the registry, found:
Hkey_local_machine\software\microsoft\schedulingagent
In my case, the corresponding is: C:\WINDOWS\Tasks, this directory does not have a log file, the last search:
Http://www.qqgb.com/Netware/windowsall/202163.html
It mentions a sentence:
– Alternatively, you can go to the Control Panel and open the Task plan and select "View Log" from the "Advanced" menu on the window.
At this point, go to the Scheduled task window above, sure enough to see the advanced, point into sure there is a view Log option, open later, sure enough to see the log, as shown in:

The log prompts are:
The account associated with the task failed to log on, so the task does not run.
The specified error is:
0x80070569: Logon Failure: The user is not granted the requested logon type on this computer.
Verify that the task is valid as the name and password for the run, and then try again.
Is the password problem, but the password has not changed Ah, no matter, in the planning task re-enter the administrator password, and then manually point down the run, incredibly can.

Windows Scheduled task failed to start