Error message when you subscribe to RSS feeds in Windows SharePoint Services 3.0 and in SharePoint Server 2007: “Page cannot be displayed”

You open a document library or a list in Microsoft Windows SharePoint Services 3.0 or in Microsoft Office SharePoint Server 2007. When you try to subscribe to Really Simple Syndication (RSS) feeds, you may experience the following symptoms:
1) You may not receive an error message that states that the RSS feeder has not installed as expected.
2) You may receive the following error message: "Page cannot be displayed"

for more click here