I am cleaning a computer for a friend. It was riddled with viruses and threats. I have managed to rid it of three major viruses and over 570 threat objects.
It had remnants of three other virus checkers that had been previously installed. I used the individual uninstall programs since none of them appeared in the install list. Windows security still thought that several virus programs were resident. I found how to eliminate that problem on the Internet.
I have installed Avast 5 free. Windows security agrees that Avast is the only virus checker in the system. I have run a full scan and found one virus that I eliminated.
I have not installed a firewall, yet, since I am going through a router. However, Avast says that it cannot connect to the Avast server to update the virus files even though I can download Avast, install and register it. My own computers that access the Internet through the same router have no difficulty updating Avast virus files.
I have run Stinger, Malwarebytes Anti-malware again, and find nothing. Spybot, and Lavasoft find nothing, either.
I have also discovered that I cannot install Zone Alarm. It crashes when I run the installer.
The computer is a Dell Dimension B110 run Windows XP, SP3.
What may be the problem?
While reading other posts, I saw that Spybot could cause problems with Avast. I uninstalled Spybot and Avast now can access its server to update.
Zone Alarm would crash when I tried to install it, so I uninstalled Avast to see if it was contributing to the problem. It was not. When I reinstalled Avast, it could no longer access the server to update the virus files.
I have solved the Zone Alarm problem by discovering that there were remnants of an earlier version that was installed in 2005 and later uninstalled. The Zone Alarm forum gave instructions to manually delete the remnants in the System32 folder and the registery.