Incase someone has not posted it yet..
MS Page
Here.
File Name: ZuneMediaCollectionResetTool.exe
Version: 1.0
Knowledge Base (KB) Articles: KB945319
Date Published: 12/5/2007
Overview
The Zune Media Collection Reset tool will reset the current state of your Zune media library. The tool will not affect any non-Zune related files or settings on your system.
System Requirements
Supported Operating Systems: Windows Vista; Windows XP Service Pack 2
Windows XP users must have Service Pack 2 or higher