>Hi All, I'm just dipping my toes in DirectX waters and have managed to create a Winform that will play audio/video files - BUT !!!! when I try to run the app on a different PC , I receive a pretty useless error message "Error in application" when trying to play a video - digging a bit deeper I find the error is related to not having the DirectX runtime installed , I've tried copying the DirectX dlls to the apps folder but to no avail - any ideas ?

Not an answer but a suggestion.
The SoundPlayer and MediaElement classes make using audio and visual sources very simple in WPF.
And you can use WPF components in WinForms....