Issue with Avast at bootup

I have Avast Internet Security. When I reboot my machine it takes over 10 minutes. There is a long period when nothing is happening except the hard drive is being accessed constantly. Does Avast run a full scan every time Windows reboots? Is this what is causing this activity / delay?
If it is not Avast, does anyone have any idea what it would be?

If so, how do I disable this activity? I cannot have it taking 10 minutes every time I reboot.

What Operating System? Are you doing a restart or, shutting it off and then back on ???

Windows 7 Ultimate. OS system restart. But, it is the same whether it is a restart or a power on.

  • Which version of AIS…?
  • Other security related software installed…?
  • Which AV(s) did you use before Avast…?

19.5.2378 (build 19.5.4444.500)
None
Uninstalled previous to installing Avast

When you uninstalled the previous AV, did you follow these directions to install Avast?
How to Successfully Install Avast: http://goo.gl/VLXde