You can disable the morning scan in Tools-> Advanced settings -> Schedules.
Scanning your computer once a day should be sufficient to keep it secure.
It seems like AVG (free) is always running scans. It seems to start about 8:00 AM and takes forever. Now they are starting to run again in the evening. I found you can schedule scans in the middle of the night, but that only gives you an extra scan, it still scans at 8:00 AM every day.
Am I missing something, or is this what it does?