You might check your settings for IE.Reset Connection Settings in IE
Since one browser can connect, while the other cannot...it might be a settings problem. These fake AV programs are known to do such.
One of the things which malware can do...is reset proxy server settings, thereby preventing connection by user.
1.Open Internet Explorer by clicking the Start button , and then clicking Internet Explorer.
2.Click the Tools button, and then click Internet Options.
3.Click the Connections tab, and then click LAN settings.
4.Make sure that there is no check to use a proxy server
for your LAN check box.
5.Click OK until you return to Internet Explorer.
Let us know how it goes.