Nothing wrong in the log, BUT, you downloaded MSN Messenger.
Do NOT install it, it's a major source for getting infections!
Also, throw that Zonealarm out and replace it with the free Sygate firewall from http://soho.sygate.com.
It goes much easier on your resources.
Personally I would also throw that Yahoo-bar out, but that's your decision.
Run HJT and have it fix those O16 entries, and you are done.
As long as you keep a close eye on those messenger programs, it's relatively safe.
I have even removed the standard Messenger, I don't believe in 'chatting'.
Email is good enough as far as I'm concerned.