This problem has frustrated me for quite some days. Although i kept searching online ,unfortunately i did not get back any resolution.

Problem:

When i click and intend to read the RSS Feeds in the Feed List of IE 7.0, it pumps up a "File Download" dialog box without opening it in IE. If i select the "find" option, it shows :

"Windows has the following information about this MIME type. This page will help you find software needed to open your file.

MIME Type: application/rss xml

Description: UnKnown

Windows does not recognize this MIME type.

You can search the following Web site for related software and information:" 

Cause of the Problem:

Because IE does not kown how to deal with this MIME type file, the content type "application/rss+xml" (and also "application/atom+xml") is not correctlly registered on  my computer.

My Resolution:

Save the following as a .reg type file and run it. The CLSID below represents xml Feed Document.

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\MIME\Database\Content Type\application/rss+xml]
"CLSID"="{528d46b3-3a4b-4b13-bf74-d9cbd7306e07}"

[HKEY_CLASSES_ROOT\MIME\Database\Content Type\application/atom+xml]
"CLSID"="{528d46b3-3a4b-4b13-bf74-d9cbd7306e07}"