Soooo - just let these things update themselves, they'll be fine - NOT.
The recent, emergency update, of Avast rendered itself useless on my machine. I uninstalled and tried AVG (you guys are the same company now right), which also turned out to be an operating system crippler. Tried reloading, fixing, uninstalling, re-installing. And finally I've had to reinstall windows.
"The UI failed to load - oooo, this is embarresing" on BOTH bits of software. Slowly programs stop responding until finally I can't even shut down without resorting to 5 seconds on the power button.
Now I have weeks of work re-configuring everything I need to get working again!
Thanks.