2009/5/26
from: http://support.mozilla.com/en-US/kb/Using+the+Java+plugin+with+Firefox#Enabling_Java
After enabling Java in your operating system and through your
Firefox options, Java may still fail to work properly. To activate
Java, try the following suggestions:
- Remove outdated Java plugin files from the Firefox plugins folder:
Note: It is recommended that you do not
copy Java plugins from other locations to the Firefox plugins folder.
Outdated Java plugins can cause Java not to work if you update Java and
then uninstall the older Java version, if plugins from the old Java
version are still in the Firefox plugins folder.
3:
- At the top of the Firefox window, click the Tools menu, and select Add-ons. The Add-ons window will open.
- In the Add-ons window, select the Plugins panel, to display a list of installed plugins.
- Select each Java plugin listed to make sure that all are enabled.
- Check if the Java plugins are correctly detected. All Java
plugins listed in the Add-ons window should match the version number of
the currently installed JRE. There should be no plugins for earlier
versions of Java. For example, if JRE 6.0 Update 2 is currently
installed, each Java plugin in the Add-ons window should be listed as
the following:
Java(TM) Platform SE 6 U2 Java Plug-in 1.6.0_02 for Netscape Navigator (DLL Helper)
- If you find Java plugin files listed that do not match your
current version, that means that the Firefox plugins folder contains
outdated Java plugin files which should be removed. This folder is
typically in the following location:
C:\Program Files\Mozillla Firefox\plugins
Java files from older versions in the Firefox plugins folder can prevent Java from working. For more information, see the PluginDoc Java FAQ.
2.0:
- In the Firefox Location bar, enter about:plugins.
- Check if the Java plugins are correctly detected. All Java
plugins listed in the about:plugins page should match the version
number of the currently installed JRE. There should be no plugins for
earlier versions of Java. For example, if JRE 6.0 Update 2 is currently
installed, each Java plugin in the about:plugins page should be listed
as the following:
Java(TM) Platform SE 6 U2 Java Plug-in 1.6.0_02 for Netscape Navigator (DLL Helper)
- If you find Java plugin files listed that do not match your
current version, that means that the Firefox plugins folder contains
outdated Java plugin files which should be removed. This folder is
typically in the following location:
C:\Program Files\Mozillla Firefox\plugins
Java files from older versions in the Firefox plugins folder can prevent Java from working. For more information, see the PluginDoc Java FAQ.
- Add missing registry entry: Sometimes a Windows registry
entry that Java needs may be missing. To fix, you should re-install
Firefox - see the instructions in Installing Firefox on Windows for installation instructions.
- Workaround if Java is not detected: On most systems,
the Java plugin files are detected via plugin scanning if the required
registry entry exists. However, in some cases, Java is not detected
unless the Java np*.dll plugin files are copied from the Java application folder bin folder.
Note:
The following steps should be executed only as a last resort, as each
time Java is updated the outdated plugin files must be removed and the
newer versions copied over. For more information, see these notes.
- Copy the np*.dll files for your version of the JRE from the following location:
C:\Program Files\Java\j2re<version>\bin\
- Paste them into your Firefox plugins folder, which is typically in the following location:
C:\Program Files\Mozilla Firefox\plugins
- Important: If copying the Java plugin files to the
browser plugins folder does not activate Java after restarting Firefox,
remove them from the folder.
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