As you may know, SharePoint includes filters to index many file types (Office docs, web pages, Tiff images, Visio diagrams, XML, etc.). What’s missing out of the box is the ability to index Adobe Acrobat files. However, Adobe does provide a free IFilter for download at http://www.adobe.com/support/downloads/detail.jsp?ftpID=2611. This IFilter works for both SharePoint 2001 and 2003 and will scan readable text in Acrobat files for indexing.
There are a few steps that you have to do to get this working:
First, find the pdf16.gif icon (look in Google Images if you don’t have it). Open the SharePoint Central Administration page, and then navigate to Site Settings > Configure Search and Indexing > Include File Types (in the General Content Settings and Indexing Status section). Add the pdf extension, and copy that image to the Program FilesCommon FilesMicrosoft Sharedweb server extensions60TEMPLATEIMAGES directory on your SharePoint server. Next, edit the Program FilesCommon FilesMicrosoft Sharedweb server extensions60TEMPLATEXMLDOCICON.XML file and add this entry in the setting with the others:
<Mapping Key=”pdf” Value=”pdf16.gif”/>
Update (Dec. 22, 2004):
There are some good guidelines here that you should review to ensure that your PDF files will appear in search results: