Windows 7, x64: For some reason with my settings, Windows Media Player insists on handling a double click on the DVD drive. The behavior I want, is to be able to manually manipulate files under VIDEO_TS. What I definitely don't want is WMP taking its sweet time loading and trying to play the DVD. (And I don't want to have to remember to right-click each time and go to Open... especially since WMP is only still installed for those rare times when using it is necessary.)
I was befuddled, of course, since Autorun/Autoplay is disabled, as is Shell Hardware Detection. Turns out, WMP integrates itself as the handler for the drive:
"%ProgramFiles(x86)%\Windows Media Player\wmplayer.exe" /prefetch:4 /device:DVD "%L"
While that whole key can be deleted, the elegant solution is to just go to:
HKEY_CLASSES_ROOT\DVD\shell and change 'Default' there from 'Play' to 'Open'.