I am working on a Dell VOSTRO 1700 running Windowx Vista SP2.
The system suddenly stopped being able to access the internet through a browser. I can ping any known address on the Internet such as Yahoo.com, Google.com, etc.
I can not get a browser to connect to the Internet. I also can not get the browser to connect to the local router at 192.168.1.1
It does not say Address Unreachable, it says Internet Explorer cannot display the webpage. Same thing with Firefox.
AVG, SpyBot Search & Destroy, and Malwarebytes are loaded for anti-virus protection. However they can not reach their servers to do updates.

I have checked the hosts file, and at first the /windows/system32/drivers/etc/hosts file was FULL of web addresses pointing to `127.0.0.1
Also, when I ping localhost, it uses ::1: as localhost. I have edited the hosts file and removed everything except localhost 127.0.0.1 and am now able to ping localhost correcttly.

I am not able to modify the lmhosts file as it seems to be locked. I can not edit it to make changes.

Even after modifying the hosts file, and rebooting I still can not get a browser to access the internet.

Yes, I've checked and rechecked "connectivity" in the browsers, etc.

Can anyone give me something else to check? I don't want to have to reinstall Windows just because the Internet doesn't work. That seems to be my only option at this point.