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I'm currently using a public computer that has no antivirus installed so I installed avast free, and I have here a portable edition of super antispyware. But those 2 cannot seem to update.

Regedit is enabled.

The account is administrator

Checked host file, but it doesn't seem to contain anything except the default. I turn off the firewall as it may be blocking the update, but no luck. It still cannot update. I really want to fix this because I'm downloading something and I don't want for it to get deleted because of viruses. This computer is running xp.

How am I supposed to get the antivirus to update, so that I could scan this computer.

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Very strange that you have permissions to install applications on a public computer. Usually they lock computers down a bit more.

Anyway... assuming you have permission to make administrative changes to this computer... there are a few things you can do.

  1. You can manually download the updates and manually apply them.

  2. Sometimes viruses and malicious software change the DNS settings on the computer in order to block or redirect DNS names associated with antivirus software. If DNS servers are defined... you can temporarily set it to DHCP to see if you can then download updates. You'll want to save the existing DNS addresses in case they are of legit use for the company that owns the workstation.

  3. In internet explorer Internet options, click on the connections tab and click on "LAN settings". Make sure that "use a proxy server..." is not checked.

Keep a record of all the settings you change and change it back when your done.


And based on your second submission of this question with the photo... it looks like the computer might already have viruses... which can block applications from connecting to the internet as well... in which case, you should refer to this.

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Try capturing packets with wireshark and see what is going on. Seeing what is going on wire always helps.

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An internet-connected, public access XP machine without antivirus. What could possibly go wrong? I'm going to rashly assume it has picked up some malware.

So here's the thing: You will probably not be able to remove this infection while it is in control of the box.

In general, to reclaim control of the system, you should try the following in order:

1) System Restore to a time before the problem manifested

2) Restart and boot into safe mode with networking (hit F8 on start up)

3) Boot from an antivirus boot disk from AVG, Kaspersky etc.

4) Clean Install

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