Vista - App fails silently on 64-bit Vista

I've developed an application that runs great on 32-bit Vista. But a user reports that when launched on 64-bit Vista it exits immediately with no error message.

I don't have access to a 64-bit Vista machine to test with. Any ideas of likely places to look? I make many calls to the Windows SDK via [DllImport(user32.dll)]. After a fair amount of searching I don't see anything saying that that should be a problem. Should it be?

Thanks for any ideas.

enable auditing and check the event log. Is it a true 32-bit app? You can't use any 16 bit on 64-bit.

As a developer wouldn't it be better for you to find or work with someone who has a 64bit OS and figure out why it fails? You have a much better understanding of how the program works...you developed it.

I'm a little confused as to what it is you're asking? Plus you don't say or describe what the program is or does.

Just curious

I read up a little on auditing. I believe it is turned on by changing the Security Policy using SecPol.msc, but unfortunately that tool is not included in the Home versions of Vista.

So far I've found no friends with 64 bit Vista. Still looking.

My application is a language for creating voice commands. The previous version (Vocola Information Pages - Introduction) works with dragon naturallyspeaking. The new version uses the powerful speech recognition capabilities built into vista.

It's written in c# using .NET 2.0. I have a try/catch around everything in my Main() routine through Application.Run(), but apparently no exceptions are fired.

.net does not give meaningful errors. You might need a debug program for C that can walk through. Can you turn on verbose logging in the app itself?

Thanks. I was just curious. I'm not a programer so it's all greek to me. I just figured if you explained what the program did someone here might be able to help you.

LOL no one you know has Vista 64, guess its just not as wide spread as we like to think.

Good luck in getting it sorted.

I suspect you have a x86-x64 marshalling problem with your native API calls. Try recompiling the app as 32-bit only. Go to Project Properties -> Build -> Platform target and change it from "Any CPU" to "x86". That will at least eliminate any 64-bit marshalling problems.