Thank you both for your very quick replies and suggestions.
I used to use avast free with privatefirewall two years ago, but it got complicated whenever there was an update for privatefirewall - my entire system would completely freeze, so in the end I decided not to use a firewall at all.
Now I've got a brand new laptop, and I've decided to harden up avast free with a firewall that has got HIPS functionality.
I am still scared of trying out privatefirewall, so I might try online armor first and keep in mind comodo.
Thank you so much,
Usnuli