Don’t know why, I responded … but message disappeared … So I tested some options: I uninstall everything, and install first Kaspersky AV. No problem Then install Comodo firewall : no problem until comodo request to reboot after upgrade. After the reboot, the problem is back, unable to launch the KAV interface (GUI) So uninstall comodo, restart: OK (KAV GUI launched successfully) Reinstall comodo, and reboot before the upgrade. Same issue. As soon as Comodo is running, KAV GUI is no more working (unable to launch the KAV GUI) I also tested installing first Comodo and KAV after. GUI is OK until the first reboot. So may I understand that KAV is incompatible with all “external” Firewall meaning that I have to install KIS? Or changing from KAV to another AV to keep Comodo as FW? What’s wrong with KAV/Comodo?