1. Go to 'Start->Programs->Accessories->System Tools->Scheduled Tasks'
2. Click on the "Add Scheduled Task' icon
3. Click on the 'Next 'button and select a program to schedule
4. Click 'Next' then select the 'Daily' radio button
5. Click 'Next' until you rach the last screen then select the
'Open Advanced Properties For This Task When I click Finish'
checkbox then click on the 'Finish' button
6. Click on the 'Settings' tab near the top of the new dialog box
7. In the Idle Time section, select the "Only start the task if
the computer has been idle for at least' checkbox
8. Select how long you want your computer to be idle before
starting the scheduled task
9. Click 'Apply' then OK
From now on, Windows will run the sceduled task when you computer is idle for the specified time you chose. However, Windows could run the scheduled task numerous times a day, depending on how many times your computer goes into idle mode.