Can you copy the wininet.dll file to c:\ and rename it as wininet.old ?? We would like to study this file and understand the infection better.
looks like there is a situation which cannot be salvaged due to the deep penetration of the infection.
I would suggest a System Restore for you at this point.
You can read more about how to do system restore here - http://www.microsoft...temrestore.mspx
Choose a time about 2 weeks or so before when you didnt have these issues with the PC.
Let me know if you want to go ahead with the System Restore