In task manager, after booting and before you manually run Avast, do you see Avast service listed?
When you used the Clean Uninstall Utility for Avast (and the others), did you use those tools under Windows Safe Mode?
In addition, you could try Avast main GUI -> Settings -> troubleshooting -> "load avast services only after loading other system services".
Reboot after the change and give Windows and Avast a couple of minutes before you recheck Avast status.