You notice how .doc files (word documents), have extra tabs when you select properties from windows explorer. How does this work. I looked in the registry and found some encrypted info under a ShellEx key for the Doc file type (HKEY_CLASSES_ROOT\.doc\ShellEx\{BB2E617C-0920-11d1-9A0B-00C04FC2D6C1} with a value of {9DBD2C50-62AD-11d0-B806-00C04FD706EC}). I copied that stuff over to the key for TXT files and got the extended tabs for TXT file properties. apparently the {9DBD2C50-62AD-11d0-B806-00C04FD706EC} value maps to a DLL (shdocvw.dll) in the HKEY_CLASSES_ROOT\CLSID\ section of the registry. unfortunately I can't get this to work for other file types, I must be missing something. what I want to do is make my own DLL to get extended info from mp3's (like winamp does), but be able to view it from the file properties in explorer.

Anyone know how this scheme works?

Thanks