how difficult it will be to create a hellow word gui in java than C# under Windows?
Even Hello World is more complicated, and even without GUI!
A "further - deeper", and not only GUI, C# is newer, that says it all.
If it is java you need to install additional software to my program?
The JRE need not know on which Windows is preinstalled and what now .NET pre-installed already on Vista.
Certainly more interested in java
Why do your apps cross-platform? It is generally always pitfalls in comparison with "nation", and especially on Windows, so please, justify your choice.