Calibre is an excellent tool for cataloguing your PDF, MOBI, EPUB and other e-book formats. Version 2.2 is for Windows Vista, Windows 7 and Windows 8 and be downloaded from http://calibre-ebook.com/download_windows. A version for Windows XP can be downloaded from http://download.calibre-ebook.com/1.48.0/.
I like the ability to define your own metadata for searching on.