This should take care of your firewall, compliments of miekiemoes, but with all the malware present it might not last until it's clean again. For all those nasties, I'd go HijackThis! Hope this helps
Open notepad and copy and paste next bold in it:
(don't forget to copy and paste REGEDIT4)
Save this as fix.reg Choose to save as *all files and place it on your desktop.
There should be a little image on your desktop for it.
Doubleclick on it and when it asks you if you want to merge the contents to the registry, click yes/ok.
Then go to start > run and copy and paste next command in the field:
Search in the list for Windows Firewall/Internet Connection Sharing (ICS)
Click "stop" there.
click OK and close the window.
Then go back to your Controlpanel and click: Windows Firewall
You should get an error then.. telling you that the service Windows Firewall/Internet Connection Sharing (ICS) is disabled/stopped and if you want to enable/start it.
So the service should be started again and you will be able to change settings in it.