By default, the LogManager reads its initial configuration from a properties file "lib/logging.properties" in the JRE directory.
Private vs. public J2RE - Installing the Java 2 SDK installs a private Java 2 Runtime Environment and optionally a public copy. The private J2RE is required to run the tools included with the Java 2 SDK. It has no registry settings and is contained entirely in a jre directory (typically at C:\Program Files\j2sdk1.4.2\jre) whose location is known only to the SDK. On the other hand, the public J2RE can be used by other Java applications, is contained outside the SDK (typically at C:\Program Files\Java\j2re1.4.2), is registered with the Windows registry (at HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft), can be removed using Add/Remove Programs, might or might not be registered with browsers, and might or might not have java.exe copied to the Windows system directory (making it the default system Java platform or not).