Hi Garyo,
Welcome to dnForum!
To answer your question, my operating system is Windows XP and my firewall is McAfee's Personal Firewall Plus, with the security level set to "Tight".
Update:
I've been checking the event log very frequently now that things are working again, and am shocked to see that my computer is receiving an average of 5-6 hits a minute - not counting pings!! And I'm on dial-up, too!!!
Also:
Don't know if this info might help someone else down the line...
Before I deleted the partition on my hard drive in preparation for reformatting it, I checked to see which ports were active, and found three listed that weren't shown before, nor are they shown now:
3001, 3002, 3003
I don't know if this will mean anything to someone who knows computers more than I do (not hard to do!) but maybe it will help someone else at some point!
Joni