Avast gone after installing Win 8.1

Hello,

After installing Win 8.1, Avast is completely gone from my laptop.
After searching, it can be found in the “Windows-old” dir’s…

Ho is this possible??
Thanks, Pieter-Jan

It would be a glitch in the 8.1 updating process, mine worked fine but there has been some problems for others.

Were you using Avast 8 before you upgraded?