This is because system restore messes up our files in the Setup folder. I.e. it reverts some of the files (but not all of them) to a previous state, leading to a bad inconsistency.
so I guess if the defense module is deactivated before restore is launched, all avast files should be reverted and be consistent again...I didn't have to use sys restore since the last build came out so I don't know how it works now, and I don't want to do it just for a test. The problem here is that you might have to go for a system restore in safe mode (in case you can't login normally for any reason), and as Avast services are of course off in safe mode, you can't deactivate the self defense module from there, and you're screwed. Only way out then is to uninstall Avast completely and reinstall once logged in normally.
On a side note, I had a cool BSOD two or three days ago. I uninstalled the firewall (just the firewall) to test another one, sometime later after uninstalling this other one , I attempted to reinstall Avast firewall, once again as it often happens with the uninstaller, the dialog box vanished a bit after I checked "firewall" in the list... and I stupidly rebooted, although I was almost sure the firewall wasn't reinstalled. Had a BSOD in the shut down phase and couldn't boot the system anymore. Went to safe mode, uninstalled avast from there, could boot and log in normally again and of course had to reinstall AIS from scratch. I was a bit upset so I run CCleaner before the new install and lost all dump files
. So, there's a serious problem with the uninstaller every time you attempt to make a change to the setup (complete uninstall runs always fine). If you're not fast enough, the process just dies. Sorry for hijacking this thread a bit but I didn't feel the need to start a new one for that. This problem has been mentioned already...somewhere in the forum (uninstaller issues...).