Hello!
I use Avast Update during several years and it required Windows restart relatively rare (monthly or even more rare). But about a month ago, Update began to request Windows restart 2-3 times per week.
Avast never found viruses on my computer. In the setup.log file, it said a reboot is needed because a resident module, aavmker4.sys, was changed. But I don't use resident protection, it is turned off.
Regards,
Eugene