How to Update Microsoft Security Essentials Virus Definitions
Look to the lower right and you will see the “system tray” triangle. Click on it to open the tray.
Look for the Security Essentials icon. If it is green you are up to date. If it is yellow/orange you either need to update your virus definitions or run a scan. If it is dark red you are in dire need of updating and scanning.
Click the icon then click “Open”. When you see the screen below, click the Update tab.
Click the Update button.
Wait for the update to complete. You should do this process at least once a week.
Now, to actually RUN a scan click the Home tab. We STRONGLY recommend you do a Full scan and not a Quick or Custom scan. Change the radio button to reflect Full and click “Scan now”.
The scan could take several hours. You may want to start it before you go to bed, leave your computer on, and it will be done by the time you wake up.
The scan can take several hours. Do NOT run this scan concurrently with any other scan. We suggest starting the scan before you go to bed, keep your computer on, and your scan will be complete in the morning.