Easy. To stop the scheduled scan, open up Security Center. Click on the 'Virus and Spyware Protection' tab (about halfway down). Click on the link that says 'Scheduled Scanning'. Click on the 'Turn Off' button at the top. Ok. Now click on the 'Home' tab in the top right hand corner. Click on 'Updates' It will probably say 'Updates:Current' Click on the 'Settings' link to the right of it. Click on the 'Turn Off' button. You should be good to go. Just remember to do a manual scan at least once a week when you can and check for updates daily when it is convenient for you. Perhaps one of the nice volunteers can drop some screen shots in here for you. I would have but I don't have that ability on this computer.
One thing, I noticed from your screen print that you have Automatic Updates turned off. Are you still being bothered by the pop-ups?
Thanks for your answer emtjoe.
Yes, I have turned it off when it happened again last night. Then, the scanning started while I was working on other stuff. I check the schedule and it was scheduled to scan at 4:00AM. That's why I was so mad. What did I do wrong? If I have to go through the stress it causes everytime I use my computer, then something need to be changed.