According to the official online installation guide for KAV 2012: "If you install any component of Kaspersky Anti-Virus 2012, then Kaspersky Anti-Virus 2012 detects and asks to manually delete... Prevx 3" http://support.kaspersky.com/kav2012/install?qid=208284358 Ditto KIS 2012 http://support.kaspersky.com/kis2012/install?qid=208284352 What's up with that .
Hmmm... that is very strange. I'm not sure why they would do that - I'm unaware of any incompatibility between Kaspersky 2012 and Prevx 3