Well I have the same issue after downloading something can't remember what anymore, now most errors are gone, but indeed I also can't load AntiVirus websites and Microsoft Sites. Also I can't load CLI.exe from ATI Catalyst Control Center it then crashes. I currently running Spybot S&D to see if that can fix my issues. I already did tried to reinstall windows, but didn't worked :O So strange

Try to open your command prompt, and run this command:

net stop dnscache

Firstly, you all are thread-hopping, so I'm not surprised that no long-term member has replied to your messages.

Secondly, no one seems to have taken any of the advice posted in one of the first few posts. If you don't want to download the Microsoft or McAffee tool, then download and use Malware Bytes. It has worked for me to remove various types of viruses, and it is highly recommended by security experts on this site.
Take the suggestions, try it, and post your results, if you want to make good use of your time, and our time.

I agree with Thinka. It sounds like the Conficker virus. You need to run you virus removal software from a separate drive that has not been compromised. I personally don't like Norton. I use Avast Antivirus (which is free for home users). You can get it from Cnet downloads. I also make sure to use Malwarebytes AntiMalware at least once a week. Just always make sure your antivirus and malware checkers are up to date.

MY HERO!!! I had gone through hell been working on this problem for over two weeks. Had run every antivirus, malware, program out there and had tries zillions of reader board tricks and advice.. nothing worked!! And all it took was three simple words 'net stop dnscache' I shed tears of JOY. I hope you will see this and realize how much your contribution has helped at least this one frustrated kitty! THANK YOU SO MUCH!!!!