Software silently fails on machine it gets installed on

I am using VS 2005, all code is C#. I created an install package for
the software.

What works: If I install it on a machine that has visual studio
installed, it works fine.

What doesn't work: If I install it on a "clean" machine (with .NET 2.0,
but not visual studio), the software silently fails with no error
messages. There is an hour glass for about a second, then it just
quits.

I'm thinking I am missing some dependency in the install package.

Any ideas?

.