Non-resident means the program is installed on your computer, ready to run if you need it, but it doesn't load at start up and doesn't use any memory or processor power under normal circumstances. The opposite of this, a resident program, means the program loads when you start Windows and resides in memory in the background. Zone Alarm, Comodo, and avast! are resident in that they are constantly monitoring, and therefore using some of your computer resources, as you surf the web or just open programs on your computer. The point about having a lot of non-resident tools is that it doesn't "cost" you anything in terms of computer performance to just have them installed.
Sometimes on forums we use abbreviations for commonly used sayings. IMO, for instance, means "in my opinion", so what I was saying is that the event viewer, in my opinion, can be very very frustrating. I recognize others may have differing opinions about it so I didn't want to imply that my statement was an undeniable fact.
C:\program files\internet explorer\iexplore.exe is normally not a threat at all - its the Internet Explorer. Comodo will sometimes show this as a hidden process that needs your attention if it opens in a covert way. For example, some help files within a program contain links to on-line help pages. When you click the link, the program you are working with opens an instance of the Internet Explorer as a hidden process in order to display the help page. In a situation like this its perfectly fine to allow the connection because you can identify the reason for its occurrence. In other cases there might be some form of malware trying to get an internet connection through a program like Internet Explorer that your firewall thinks is safe. Its a way to trick some firewalls into allowing a connection. If you ever see this happen - Internet Explorer (or anything else for that matter) trying to connect when you don't expect or or can't reasonably explain it - its best to block the connection and investigate.
What I have on my computer is probably more than you want. I have some specialized malware removal tools that I've never needed but can open in order to give advice to others that might need to use them. I also have some overlap, like AVG Antispyware and A-Aquared, that you might not want to bother with. But if you have the following you should be good:
avast!, plus a back-up virus scanner (non-resident) like ClamWin or Bitdefender Free
Comodo Firewall
Ad Aware SE
Spybot Search & Destroy
AVG AntiSpyware
SuperAntispyware
WinPatrol
SpywareBlaster
Some would recommend an alternate browser like Firefox, but Internet Explorer is OK imo
EDIT: Sorry Cloussau - I duplicated some of what you said but I spent so much time typing it I didn't want to start deleting things.