I'm in the process of repairing a friends computer after it having contracted a virus posing as Avira Anti-Virus (ironic?)

Anyway, after eliminating the virus, the computer now will not connect to any network of any form. It recognises wired and wireless, starts connecting, goes to "renew IP address" and then immediately jumps to no connectivity. I think the problem is something to do with it trying to define its own IP address, instead of receiving one from the network, but I have reviewed every IP, DNS or Internet related setting I can find.

My question is whether any similar behaviour has been encountered by any of the wonderful people on this board, and how it was resolved. The troubleshooting steps I have taken are as follows:

Restart, enable, check windows zero config, windows wired config Check every setting I can find in wireless settings and ensure nothing is set to restrict IP Boot in safe mode, restricted service and diagnostic modes Two different wireless networks, two wired plus one ad-hoc. All failed.



Quick things to check- make sure there are no proxy servers suddenly configured in your web browser (viruses often make changes here). It wouldn't cause the error you're seeing, but it's worth checking anyway following an infection.

More importantly- is your PC set to DHCP? Double-check that it is. Do an IP config and see what IP you're getting (if any).

Fixing WinSock:

There's a very good chance WinSock got corrupted by the virus. It's possible to fix this.

  1. In Registry Editor, navigate to locate the following keys, right-click each key, and then click Delete: HKEY_LOCAL_MACHINESystemCurrentControlSetServicesWinsock HKEY_LOCAL_MACHINESystemCurrentControlSetServicesWinsock2

  2. When prompted to confirm the deletion, click Yes. Restart the computer after you delete the Winsock keys. Doing so causes the Windows Operating System to create new entries for those two keys. If you do not restart the computer after you delete the Winsock keys, the next step does not work properly.

  3. Install TCP/IP:

    • Right-click the network connection, and then click Properties
    • Click Install.
    • Click Protocol, and then click Add.
    • Click Have Disk.
    • Type C:Windowsinf, and then click OK.
    • On the list of available protocols, click Internet Protocol (TCP/IP), and then click OK.
    • Restart the computer.
  • Tried winsock, for a moment thought it was successful - the connection went to connected for a fraction of a second before going to limited or no connectivity. And C:Windowsinf or C:Windows.inf or C:\Windows.inf all came back with nothing. – George Pearce Feb 24 '13 at 18:33
  • What does IPCONFIG say the IP address being acquired is? (If any.) – Austin ''Danger'' Powers Feb 24 '13 at 18:34
  • Autoconfiguration IP address is which is totally out for the router setup (192.168.....) - any suggestions as to where I could configure that? – George Pearce Feb 24 '13 at 18:36
  • Type "ncpa.cpl" in CMD or the "Run" dialogue box, then press enter. Right click on the network card in question, select "properties". Select "Internet Protocol (TCP/IP)", then click "properties". Here you can first try making sure both radio buttons are set to the top (automatic) options. If that doesn't work, you could try setting a static PC like "" (or whatever matches your subnet). Subnet mask would be "" and gateway would be your router's IP "" (or whatever it is). – Austin ''Danger'' Powers Feb 24 '13 at 18:47
  • Both are set to automatic, and manual configuration seems to have no effect. I thought this too a few hours ago (didn't check IP though) - is there somewhere else this stuff might be set? – George Pearce Feb 24 '13 at 19:07

My problem was solved by the first line in the first line from Austin Powers, "no proxy servers suddenly configured in your web browser."

Now I want to find out how the proxy got set!

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