If you configure the Firewall of Windows Vista for outgoing connections, you have to consider some restrictions in the use of AntiVir WebGuard. This only applies to Vista systems, on which some programs for outgoing connections should be blocked by Windows Firewall.
When AntiVir WebGuard is active, Internet applications receiving data over HTTP are not blocked, as long as the remote port is 80 or 8080. WebGuard runs as transparent proxy in LSP, to completely scan HTTP traffic. Thus it scans and blocks suspicious data traffic, as well as dangerous websites, regardless of the browser.
As workaround, you can block the access for certain users in NTFS file systems. Otherwise, you can remove the WebGuard module from AntiVir's setup routine, under Control Panel → Add or Remove Programs.