Using AVG antivirus now. Completely free. Check the sticky
thread about spywares.
Why IE is called IE, ask Bill Gates.
ZoneAlarm is free as well, check the sticky thread. ZoneAlarm no
need to configure, everything by default is good enough, unless you
are panicky about security. There are other firewalls in the sticky
thread as well, and they are all completely free.
For AVG, it will auto update, but if your computer is off at that
time, it doesn't seem to update. So you need to update manually.
You can avast! as well, it's another free antivirus.