Not a valid Win32 application

Question

I have a project I have built in Visual Studio 2010 on a Windows 7 machine. It compiles and runs without a problem.

When I place the application on a XP machine with

Answer 1

In the project properties, is the project targeting "x64" rather than "Any CPU"? (It does seem to say "machine (x64)" in the bindump header, which sounds like this may be the issue)

Is it targetting .net 4 full or client profile? If full, check that your XP has the full profile installed, not just the client profile.

(Unlikely to be related, but) Is the Visual Studio 2010 redist installed on the XP machine?

Check that the file hasn't been corrupted during the transfer onto the Win32 machine (e.g. copy it back and diff it or run it on your Win7 box)