Cannot deinstall Avista Antiviruns

I don’t know how the software was installed, but I have an abonnement from Kaspersky. I need to carry out an update of the latter, but I am told I have to delete Avista Antivirus due to incompatibility. The Windows (8.1) deinstall does not work. I downloaded the Avista Clear program, but that goes straight into a loop and doesn’t come out of it. Does anybody have an idea how ot solve this problem. It appears that Avista does not want direct support contact, unlike Kaspersky.

Never heard of Avista before, post a screenshot.

How to Successfully Install Avast: http://goo.gl/VLXde