Guys,
I had exactly the same problem on a friends PC.
In the end I found a load of spurious entries in the hosts file.
This is located at c:\windows\system32\drivers\etc and is called hosts it has no file extension.
Just open it with notepad or something similar.
Unless you have explicitly added any entries then the only one that should exisit is
127.0.0.1 localhost
Make a backup of it first then delete all of the other entries.
Tim
P.S.
Just as an update, make sure you scroll right to the bottom of the hosts file, as at first glance it may appear to be 'clean' but the entries that you need to delete are at the bottom of the file.
I had exactly the same problem on a friends PC.
In the end I found a load of spurious entries in the hosts file.
This is located at c:\windows\system32\drivers\etc and is called hosts it has no file extension.
Just open it with notepad or something similar.
Unless you have explicitly added any entries then the only one that should exisit is
127.0.0.1 localhost
Make a backup of it first then delete all of the other entries.
Tim
P.S.
Just as an update, make sure you scroll right to the bottom of the hosts file, as at first glance it may appear to be 'clean' but the entries that you need to delete are at the bottom of the file.