PDF Icon does not show in the document library while uploading the pdf file.

Steps Taken for resolution

1. Copy the PDF.GIF file to “C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\12\Template\Images”

2. Edit the file C:\Program Files\Common Files\Microsoft Shared\Web server extensions\12\Template\Xml\DOCICON.XML

1. Add an entry for the .pdf extension.
2. Reset the IIS
3. After that we were able to view the pdf icon in your document library.