Identifying the version of Java effectively in use by LimeWire is possible in the "Options->Error Reports->View Example Report" screen.

But if you run Limewire through the "LimeWire.exe" program installed with the downloaded installation, it will simply use the default version of Java indicated by the Java icon in the Control Panel: there's a pane that lists the correctly installed Java JRE/JDK versions, and indicates which one will be the default when starting a Java program.

This setting is the one used in the standard JNI interface used by Limewire.exe

(JNI is a standard component/interface of Java, which binds the Java Virtual Machine to the native OS, and allows a native program to instanciate a Java Virtual Machine; Limewire.exe does not indicate where Java is located, it simply uses the JNI services that will locate themselves the JRE to use according to the standard Java installation and behavior, i.e. using the settings you have configured in the Java Control Panel on Windows).

A system can have multiple JRE installed. If you have several versions of Limewire, with one starting with a local invokation of java.exe in its installation directory, and the other started by "Limewire.exe" using the JNI interface, the two will not necessarily use the same settings, because "java.exe" first tries to locate a JRE in its own directory, before seeking a JRE through the Java Control Panel settings. This means that two independant versions of Limewire could run.

You can avoid this problem by locating where a "jre" directory is installed on your system. You just need to keep one JRE on your system. (the JRE installed in older "international" versions of Limewire are now old, as they were in version 1.3.1, instead of the recommanded version 1.4.x, or newer beta versions 1.5.x which works like a charm and adds further performance enhancements; now Limewire will be shipped without bundling the Java installer; but it will be able to download and install separately a JRE before proceeding to the installation of the Limewire application itself and its components: this way, you don't need to bother about what to do with multiple JREs, as all can be centralized and managed in the Java Control Panel).

So open your Java Control Panel, and locate the JREs, keep only one (the latest), and make it the default. Apply the changes and exit. Now remove all extra JREs from your disk (yes you can delete the "jre" sub-directory that may persists in the installation directory of an older version of Limewire, because even such old Limewire version will be able to use the new Java version configured in the standard Java Control Panel).