> it is on
http://www.ventismedia.com/mantis/view.php?id=5571
Whoops! Filed by me!!

Sorry and Thanks. (Note to beginner self: remember to cross-link from forum...)
>>> Can you give me Registry value of "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Media" -> "Format" property?
> BTW that Registry entry must exist as it shows current version WMP and Windows media Format libraries installed.
Must... or should?? Hard looking did not find it.
BTW, on a second fresh Windows XP SP2 installation, but plus WMA 11 update, I do see
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Media but empty - so no "Format" property.
> Do you have
HKEY_CLASSES_ROOT\Software\Microsoft\WindowsMedia\Setup\BlockingRefCounts\App registry entry?
That first installation is gone, but on this second (with WMF11) - no.
HKEY_CLASSES_ROOT\Software\Microsoft holds only
MediaPlayer
Multimedia
Windows
Windows NT
It sounds like it would be worth you setting up Win XP SP2 in a VM.