For Windows Vista/Windows 7

• 1). Open the Control Panel.
  
  
• 2). Select "Administrative Tools" under the System and Security heading.
  
  
• 3). Select "Task Scheduler" from the list of utilities.
  
  
• 4). Select "Disk Cleanup" from the list of scheduled tasks. From the "Actions" pane, select "Delete." After confirming this action, Disk Cleanup will no longer be scheduled.
  
  

For Windows XP

• 1). Open the Scheduled Tasks utility by following this path: Start> All Programs> Accessories> System Tools> Scheduled Tasks.
  
  
• 2). Find and select "Disk Cleanup" on the list of scheduled tasks.
  
  
• 3). Right-click "Disk Cleanup" and select "Delete" to remove Disk Cleanup from the scheduled tasks.