Error message when you try to start the Task Scheduler service in Windows XP: "Error 1717: The interface is unknown"

Refer http://support.microsoft.com/kb/915156

Solved

• set startup type of "Event Log" to automatic and start it
• set startup type of "Task Scheduler" to automatic and start it

To resolve this issue, start the Event Log service. Then, start the Task Scheduler service. To do this, follow these steps:

Note You must have a computer administrator account to follow these steps.

1. Click Start, click Run, type services.msc, and then click OK.
2. Right-click Event Log, and then click Properties.
3. In the Startup type box, click Automatic, click Apply, and then click OK.
4. Click Start, wait for the progress bar to complete, and then click OK.
5. Right-click Task Scheduler, and then click Properties.
6. In the Startup type box, verify that the startup type is set to Automatic.
7. Click Apply, and then click OK.
8. Click Start, wait for the progress bar to complete, and then click OK.
9. Exit the Services snap-in.