Task Scheduler Service not running

Problem: Task scheduler service won't start under XPsp2. It returns a "file
not found" error code 2.

Solution:

a) sfc /scannow in command prompt and insert if asked to. Hopefully it will recopy all the required files to windows directory again. Then you can give a try after one restart.

b) Navigate to "c:\windows\inf" folder. The inf folder is a hidden folder,
you /may/ need to unhide folder and files in Folder Options to view the
INF folder.

Locate and right-click "mstask.inf" to select install.

Hope this helps.