My 2 cents worth perhaps incorrect if so please correct
If i can download a file from the internet with a firewall no problem why wouldn't me clicking the download button on one thing and it turn into something COMPLETELY different completely counteract all your security and firewall protection?
Also i have router firewall pc firewall and all this other stuff and the viruses still find a way in my machine no problem
My old xp witch i found better to turn off firewall dosent seem to get infected anymore than my seven with firewall protection...... probably due to router firewall.
Just personal opinion i havent been to impressed with all this security stuff so far all it has done is slow down my pc :P
Malwarebytes on the other hand it is great

wouldn't have a pc without it

those other antivirus people should take advice from thoses guys.
Malwarbytes has never slowed down my machine NEVER conflicts with other programs and almost ALWAYS fixes the problem......when it doesn't i usually reformat