I have a job that runs on a Windows 2003 server every morning using Windows Task Scheduler, and that job relies on cscript.exe (to execute PAL.vbs).  I have spent probably a day trying to figure out why my job is no longer working after a recent automatic Windows Update.  I altered the program I wrote to shell to cscript.exe to include logging and stared at the log output with a puzzled expression for a long time.  My job ran completely fine in interactive mode, and would run fine if the job was set to run as a user logged in (without the "only run when this user is logged in" checkbox checked).  Completely unattended however, that was a no go.  Security context or paths or something was just not making it down the shelled cscript.exe.

Turns out that the "HID Input Service" causes the problem, and a recent Windows update caused it to emerge on my Windows 2003 system.

To fix it you must disable the HID Input Service (set its startup action to "Disabled") then reboot the computer.  The HID Input Service is responsible for the extra key buttons on your keyboard, like Calculator for launching calc.exe.  Not a big loss.

Sources:

http://ewbi.blogs.com/develops/2003/09/scheduled_tasks.html

http://support.microsoft.com/default.aspx?scid=kb;en-us;812400