Some things should just be easy. I’ve committed a bunch of registry utility functions into JNA’s platform.jar, all with unit tests. You don’t have to break your head with Win32 API, just use
com.sun.jna.platform.win32.Advapi32Util and the following functions.
REG_MULTI_SZ support and registry key and value enumerators next.
If you were using JnaContrib Registry classes for these purposes before, you should switch. The code in the latter doesn’t do a very good job at consistently throwing exceptions when a key cannot be read or found.