Customizing Right-Click Menu Entries on Windows 7

[Varian 6]

In building Windows 7/2008 R2 Images I have noticed that a few file extensions "resist" the traditional ways of adding right-click menu extensions. Usually I can add the relevant custom registry entries in the HKCR or HLKM\Software\Classes and I'm done. With certain extensions (like .wtv) I can add the entries but the customizations never appear. I have been able to get a COM application to register itself with .wtv, but nothing in the static "shell\command" will show up. Par example:

RegWrite('HKLM\SOFTWARE\Classes\MediaCenter.WTVFile\shell\DVR_Rename', '', 'REG_SZ', '"C:\Custom Programs\DVR Date Change Script.exe" "%1"')

The registry key is added (I also do the same for HLKM\Software\Classes) but the option never appears in the menu entry for .wtv files. I assume that this is something that has happened since Vista(since this worked under XP all of the time I have tried it), but I was just wondering if any MS gurus may be able to explain why and how to overcome this.

Edited October 22, 2010 by Varian