according to google,it modify the DNS server settings to point to an external site. This will prevent normal connectivity to the Internet, as domain names cannot be resolved properly.I was attacked by these kind of virus too.I somehow managed to get rid of it by deleting the connection then scan it while in safe mode.After that,i made a new connection.It works I don't recommend using avg coz it's detection is not really good.Otherwise,try this link,hopefully it helps: http://www.exterminate-it.com/malpedia/remove-qhosts

i guess reformatting is the best way.

Trojan.Win32.Qhost modifies Windows host file, thus forbidding user to access well known virus protection websites, because the hosts file is used to map IP addresses to host names.
Hosts file location (XP, 2000, NT systems): %System%\drivers\etc\hosts.
Hosts file location (9X systems): %Windows%\hosts.
Virus database update service cannot be accessed as well, so your anti-virus software is not able to update. Trojan.Win32.Qhost is a risky trojan and should be removed immediately to keep your anti-virus program work properly.

Can you access to the internet? Try downloading PcTools internet security.It's trial but there's free promotion for a year by pctools.The virus kept coming back because it infected your network.

since you have tried almost everything,i suggest it's time to reformat your hard drive.I have been attacked twice,the first time i have to reformat my hard drive but i managed to get rid of it at the second time.

try open task manager.. is there anything called "Win32/Qhost" in your processes?

do you get redirected to other websites?

what's the problem? Coz i don't understand the pic