I would like to stop all automatic updates temporarily
in avast! 4.x Home in order to reconfigure the
network connection without problems.
Can this be done by killing some processes?
And then rebooting the system when the reconfiguration
is done?
Best regards, Sven Ingvar
Hi sijon1! 
The answer to your question is no. You don’t need to kill any process. All you need to do, is just to set avast! to update manually by going to avast! settings… ->Update (Basic) and switch the update option to manuall, so you can perform your network tweaking without excurseing on avast!.
EDIT:
When you finish, just turn back avast! to automatic updating, which is done wiseversa described process. see picture attached 8)