Two anti-viruses will conflict with each other. I think leftovers from Kaspersky are conflicting with avast.

First boot into safe mode & uninstall avast. Boot into normal Windows. Next follow the instructions on using the Kaspersky removal utility. http://support.kaspersky.com/faq/?qid=208279463 Reboot.

To be sure to get a clean install of avast, run the avast uninstall utility. Reboot. Now reinstall a fresh copy of avast.

Welcome to the forum. :slight_smile: