I'm a bit confused here. If you set your firewall, use a router, or some such..then do not do any emails...not even set that up until you get your AV in place... or even have a fairly current install of your AV always handy.... then do MS updates prior to going anywhere else online...shouldn't you be fine? About 99% of the viruses arrive via MS Outlook... most of the spybots and stuff come from web sites..and installing crap like Real stuff.... The viruses don't just normally come flying through open ports and stuff....unless maybe you're not reformatting prior to install or something and they're still active on your system. or do I have it all wrong?

Humankind has not woven the web of life. We are but one thread within it.
Whatever we do to the web, we do to ourselves. All things are bound together.
All things connect......Chief Seattle, 1854