Try updating the folder list
De-selecting this option will prevent Java applets from running in any browser and the Java plugin will no longer appear in the Firefox or Sea Monkey Add-ons Manager or about:plugins list.
To view or change this option, click the Java icon in the Windows Control Panel or Mac OS X System Preferences to open the Java Control Panel, then select the Security tab.    Mac OS: You can download Java from Apple Support Downloads (Java 6 and below). Windows and Linux: You can download Java here or you can select the offline (full) installer for your operating system from this download page.
  If you prefer an offline installation, go to the Java Downloads page (see above for links) and save the Windows Offline installer to any convenient location, close your browser and run the installer.
 Starting with Java 6 Update 10, Java updates patch the current version by default instead of adding an additional version.
 If you don't need 64-bit Java, there is no reason to have it installed.
If both 32-bit and 64-bit versions of Java are installed, the Windows Control Panel will display only the 64-bit Java Control Panel.
You can then go to the "Update" tab and click the "Update Now" button, to see if an update is available.
This utility allows browsers other than Apple's Safari to use the most recent versions of Java on Mac OS X.
 The Java Embedding Plugin is no longer needed in newer Mozilla browsers such as Firefox 4 and is no longer included.
Many web pages use Java applets for interactive content such as online games. Starting in Firefox 3.6, Java will not work unless you are using the Next-Generation Java Plug-In (included in Java 6 Update 10 and above).
To run these Java applets, you need the "Java Runtime Environment" ("JRE") installed and enabled.  Important: Mozilla adds outdated or insecure plugins to its Add-ons Blocklist as a security measure.
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In such cases, you can access the 32-bit Java Control Panel for Java 7 by running C:\Program Files (x86)\Java\jre7\bin\(press "Windows key R" to open the Run box).