I am using Vista on my laptop, and have noticed every now and again, the Windows Defender icon appears on the taskbar. When I open it it says I havent scanned for 4 days, yet I have set Defender to scan every day at 1800hrs - anybody know why it isnt scanning automatically?

Are you following these instructions? "Schedule when Windows Defender scans your computer".

Did you check to make sure the service is running?

• Click on Start > Control Panel > System and Maintenance > Administrative Tools and double-click on the Services option.
• When prompted by User Access Control, click the Continue button. If you are not prompted, you have either disabled UAC or are logged in with an account that does not have the ability to run with administrative privileges.
• In the Services applet, look at the Status and Startup Type entries next to the Defender service.
• When a service is running, it will be listed as Started in the status column. If the Status column next to a service is blank, that means the service is not running.
• If it is stopped, double-click on the Defender service to open the Properties page.
• In the Properties Window > General Tab that opens, click the "Start" button.
• From the drop-down menu next to "Startup Type", click on "Automatic".
• Click "Apply", then "OK" and close any open windows.

Thanks for that, i'll give that a try

I have tried that and it said it was automatic , and was running- so i set a time for it to automatically start, but it never did, unfortunatley im back to square one - any ideas?

"Windows Defender Support & Training" click the link titled Phone Support