I'm usually pretty savvy when it comes to de-virusing a computer, but this one has got me completely stumped. I recently noticed a browser hijack where in all browsers, any result from yahoo.com is redirected to porn. Also, every update (anti-malware application download, update, or windows kb download, or windows update) will fail, sometimes with a DNS failure, sometimes with a 404 at all times. I have tried to download Ad-Aware (updates fail, returns 404) AVG Antivirus (updates fail, dns times out) Avira AntiVir (updates fail, returns 404) Microsoft Windows Update fails to open (just redir's back to windows update) Microsoft KB Downloads (Service Pack 3, various KB patches return 404) Can anyone help identify this? I updates avira, and avg manually (via a cd from another computer) and they say the computer is clean. All Conficker scan tools say the computer is clean. Microsoft live onecare says the computer is clean. I also add that I'm going to format & reinstall, but I would really like to know what I have (had) so that when I am trying to recover data from the old HDD I don't reinfect myself. Thanks in advance. Any help would be much appreciated.