Hi Tom,
yeah it's a nightmare out there now.
The best single thing to prevent all of these hijackings, spyware is simple, Do not use Internet explorer. There are far too many unpatched security holes in IE.
Use Mozilla or Opera or the one most of us here use Firefox.
http://www.mozilla.org/products/firefox/
I haven't used IE for quite a long time. now.
Firefox is stable , works well and is far safer.
Kerio is a good firewall, I've noticed many people prefer the older versions though. In particular version 2.1.5
This link is a dedicated Kerio-Tiny forum which has links to download the older as well as newer versions of Kerio, as well rule sets etc.
http://www.dslreports.com/forum/kerio