Look for a hosts file in your Windows\System32\drivers\etc folder and open it with notepad. Do you see any entries without a # in front of them?
If you see the offending entry, delete that line or put a # in front of it. Hopefully that will allow it to work normally, but if it comes back, you may have a virus. Some anti-virus programs now have a setting to keep anything from changing the hosts file.
Regedit was the first thing I tried. Whatever this is, its hidden well and I really dont like it!