Please advise on my problem. I can not access the Internet from any of 3 web browsers. Chrome (the most informative) suggests "Error 137 (net::ERR_NAME_RESOLUTION_FAILED): Unknown error". This is on a Windows Vista PC that dual boots to MultiPoint Server, from which I have no problem accessing web sites so I rule out hardware and ISP as being at fault. Entering the IP address direct in a browser gives an error as does booting to Safe Mode and trying from there. I was able to 'resolve' this issue by using system restore to get to a point before Windows Live Mail was installed. I then reinstalled it and it worked fine, as did web browsing. I then tried installing BitDefender Internet Security and that failed to the extent that even as owner of its files with an ACL granting full access I was not able to delete them. I eventually did so by booting to MultiPoint. Hosts. looks fine and no virus is suspected. This is a fairly new installation. I feel sure I am missing something simple - well I know it actually, just can't think what.Thanks.

This was resolved by booting into safe mode with networking then running the 2013 BitDefender uninstall tool as Administrator. After a reboot the installation of BitDefender proceeded normally and Internet connection with web access was possible.Thanks.