I am going through your HiJackThis log but wanted to post this immediately. Part of your problem is you are running two anti-virus programs, this is an absolute No-No. Rule is only ONE anti-virus program and ONE firewall on a computer. The Zone Alarm Security Suite contains an anti-virus program and you are all ready running Norton. This Zone Alarm version also contains an anti-spyware portion and the firewall of course. Since it is really the firewall you want I recommend that you immediately uninstall, COMPLETELY, the Zone Alarm Security Suite and then do a file search on the computer by going to Start, Search, Files and Folders and look for everything Zone Alarm. Delete whatever you find. THEN reboot the computer and if you wish to use the Zone Alarm firewall download and install the Zone Alarm Free Firewall
Now you will have to scroll clear to the bottom of the page and click on the "I want only the basic Zone Alarm protection" button.

Another thing you need to do is disable the SpyBot TeaTimer portion of that program. It can cause problems on some computers AND if we do find some malware it can make it very difficult to remove. So disable TeaTimer like this;
To close Tea timer and to disable it from starting with Windows when you restart, open Spybot S & D, open the Tools menu on the right pane and click on Resident and uncheck Resident "Tea timer"(Protection of over-all system settings) active. Exit the program. Restart the Computer.

Another thing running all the time in the background is AdAware Service. This is a new feature of the AdAware 2007 Free. Frankly, I don't like it as it does consume some resources. The supposedly easiest way to stop this is to set the process to manual by running services.msc. BUT then you will find that Adaware will restart the service anyway. Honestly I would consider uninstalling AdAware 2007 and going back to AdAwareSE
I would then only use AdAwareSE and Spybot for weekly scanning and not use their background items. DO use the Immunize feature of SpyBot however, it does make a difference.
I will go through your HJT log and see what else may be causing your resource usage to be so high.
Judy