This Microsoft Support article seems to relate to this bug (hotfix available):
The "Search programs and files" box does not display search results correctly in Windows 7 and in Windows 2008 R2.
On a computer that is running Windows
7 or Windows Server 2008 R2, you try
to search for an item on the computer
by using the Search programs and files
box. However, the search results are
not displayed correctly. Only the
category headings of the categorized
search results are displayed, such as
Programs, Control Panel, and
You need to view the above article using Internet Explorer. If the update is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. To download the hotfix, click the "View and request hotfix downloads" link, then "I accept" and follow instructions.