Finally the problem has not dissapeared… :cry:
I still have the same problems. It’s very strange because the problem appears only every thursday or friday: I can’t connect to the web anymore and something is using the svchost.exe service and sends traffic to the web. I have disabled all useless and dangerous services which use the svchost.exe file but the problem is still remaining. And I found something strange too : I can connect the web again when I use a link in some application (for example the help link in zone alarm). Totally confusing… :-[