Windows Defender - Change Scheduled Full Scan Time

Tags Antivirus


  • The Windows Defender full scan slows my computer down; how can I adjust the time when it runs?


  • Oregon State University
  • Windows Defender


When Windows Defender is running a full scan, CPU and disk utilization can be very high, causing the computer to become slow and unresponsive. You may wish to adjust the time that full scans are started so that the computer is not in use while the scan is running.

Windows Defender scheduled scans are managed in the Task Scheduler application. You will need local administrator rights to make changes.


  1. Open the Windows Start menu
  2. Enter: Task Scheduler
  3. Right-click on Task Scheduler and select "Run as administrator"; enter your administrator username and password when the UAC prompt comes up
  4. Browse to: Task Scheduler Library -> Microsoft -> Windows -> Windows Defender
  5. Double-click on the "Windows Defender Scheduled Scan"
    • Note: if Windows Defender is currently running a scan, it will be listed on this screen
  6. Select the "Triggers" tab
  7. Select the "Weekly" scan and click Edit
  8. Set the day of the week to run and the start time as needed; click OK

You may also want to review the options on the "Conditions" tab and adjust one or more of the following:

  • Start the task only if the computer is idle for: 5 minutes (or more)
  • Stop if the computer ceases to be idle
  • Restart if the idle state resumes
  • Start the task only if the computer is on AC power
  • Stop if the computer switches to battery power


For assistance, contact the Service Desk.


Article ID: 107614
Wed 5/13/20 5:12 PM
Thu 5/14/20 8:41 AM