How can I fix "No site configured at this address" message?

How can I fix"No site configured at this address" message in IE9-Win7-when I load "http://www.yahoo.com"/?

I have yahoo home page set as my Internet Explorer home page.

I'm on windows 7.

I'm using Internet Explorer 9.

I tried deleting cookies.

I tried resetting IE to default settings.

I ran Malwarebytes.

I ran Avast Anti-virus.

I ran Ad-Aware.

I ran Chkdsk.

I Defragged my PC.

I ran Disk Cleanup.

I Reset my cable modem.

I Reset my router...

Everything I can think of... And I keep getting the message "No site configured at this address" or 404 error message when I try to connect to Yahoo homepage. Anyone have any ideas I can try to help fix this? Sometimes It connects after I delete cookies, or just after I restart my computer, but soon after I get the message again.

On a side note : I've even downloaded and installed Firefox and get the same results.

Any suggestions please?