Use DirectX Audio Functions In Program For WinXP / Vista?

I've been fighting for weeks now to make a simple music playback program. It would function much like Windows Media Player without the visualisations and playlists. I'm writing this on a Win7 box, but it needs to work on XP and newer.

I say fighting because I'm severely annoyed at how MS has worked some items and it's taken many days to go through everything only to find that it doesn't work.

I started by using WMP in VB Express 2010 and having it play my music. Simple, but not portable. I copied my .exe to a WinXP machine and it blew up. I copied it to a different Win7 machine and it doesn't run (I can double-slick all day, nothing happens,
no log entries, nothing....)

Then I find that there is an issue with the GUID of media player on different computers, and it'll most likely fail to run when you try to use it on other machines than the one the program was built on.

So I gave up on that.

I then figured I'd use DirectX. It's on XP and newer already, and is supposed to be backwards compatibile so if I build my app on Win7 it should still run on XP and such. I did that, and it works fine on the machine I built it with (again). My shuffle works,loop/repeat works, got my own version of a playlist and it all works. I copy that to another Win7 box and it doesn't run at all. It's setup as .NET 3 so I can be sure of compatibilty with WinXP.

For grins, I gutted all the code in my VB app involving calls to Directx and built that. It runs fine on other computers, including my XP test box. So I know the problem revolves around DirectX somehow.[code]...