Took a look at the hijackthis log.
There is a lot of stuff I don't know anything about, and a lot of leftovers (Forefront Endpoint Protection for instance etc.) and some tweaks to the system. I see Webwasher is running also.
I dare not give any advice, I am not specialist enough. Anyway it looks to me, that on this system a lot of tweaking, installing and uninstalling, testing and specific network setting has been performed in the past.
If it was my system, I would probably set up the whole thing anew.
Maybe someone else has better knowledge and will give detailed advice.