Charles’ computer wasn’t getting any internet connectivity after a automatic windows update. It turns out that Zonealarm Firewall was the culprit in this case. When Windows started, Zonealarm always died with an error message.

1. I uninstalled Zonealarm
2. Activated Windows Firewall
3. Disabled File and Printer Sharing and other useless services from the network interface
4. Tweaked the “exceptions list” on the Windows Firewall
5. Installed a free antivirus and detected and removed two trojans
6. Updated Ad-aware and scanned the computer

1. In the end, I needed to clean manually a spyware by removing it from the registry

Another problem was that his wireless connection kept dropping because the radio spectrum was too busy in his building. He already tried to change the channels but that did not solve the problem, it only made it to appear more seldom. I connected the two desktops with an ethernet cable.

Lesson: If you have two desktops it might be worth it to connect the with a cat5 cable if your wireless connection is not reliable. It also increases the security of your network.