Your "installation" will need an already installed JRE (with jre/bin
folder with java.exe
and all the other files) for a "bundled" JRE. You can't pack an Java installer with launch4j.
Doesn't it show to your friend the option to download and install Java if it doesn't find a JRE?
If you want to install Java alongside with your application, take a look at NSIS.
There's another one: IzPack. It creates multi-plataform installer. But, as it depends on Java, it's the same case of launch4j -> you'll need to download and install Java first. (I didn't use IzPack yet, but when I was looking for a solution, it was one of my alternatives.)