There are a few reasons you might receive this error message. Make sure you are using the "No proxies" connection setting.
To select this setting:
If you are unable to connect using the "No proxies" option, you might not have the ability to use the webcam feature.
Your firewall must permit outgoing TCP connections on port 5100. Make the following changes to your firewall:
Most Internet service providers (ISPs) don't have firewalls or proxies, but you should contact your network administrator or ISP for accurate information.
Note: You might be running XP's built-in Internet Connection Firewall (ICF) without your knowledge.