The standard EXTENSION directory is a directory containing JAR files that is searched automatically by the Java runtime and compiler. If you've installed the JDK (not the just the JRE) you may well have two separate ext directories, one of which is used for compiling (typically SOMEWHERE like C:jdk1.3jrelibext) and the other of which is used for running code (typically somewhere like C:Program FilesJava Softjre1.3libext). The wrong JAR FILE in either directory can get in your way (though at different times). Furthermore, the RIGHT JAR file has to be in both directories.

The standard extension directory is a directory containing JAR files that is searched automatically by the Java runtime and compiler. If you've installed the JDK (not the just the JRE) you may well have two separate ext directories, one of which is used for compiling (typically somewhere like C:jdk1.3jrelibext) and the other of which is used for running code (typically somewhere like C:Program FilesJava Softjre1.3libext). The wrong JAR file in either directory can get in your way (though at different times). Furthermore, the right JAR file has to be in both directories.