Avast Internet Security 2015 - scheduled scans

It looks like there is a scheduled scan that is happening and I want to modify it. Twice today, my pc ran a scan and then shut down. I checked what I have scheduled. The scan that shut down my pc wasn’t one that I scheduled. I schedule mine for after midnight. The two times it ran and shut down were at 11 a.m. and 10 p.m. Both times I was in the middle of something, and did not see that the scan had started. The report screen popped up and I went to close it and that’s when Avast shut down the pc. Is this normal? I’d like just use the scans I set up.

This is continuing to happen. It’s not a scan I set up. My pc is being shut down after a scan that I didn’t schedule. I see the notice for a split second, asking me if I want to reboot/shut down and before I can click, it shuts down. I’ve been through all the scans that I set up and it’s not something I’ve scheduled.

What OS/SP ?
What exact version of avast ?
Any other security (related) software installed ?

I don’t have any other security/av software running. Only Avast. I have the Windows stuff installed but it’s turned off. My pc is Windows 7.