Java 2 Runtime Environment 1.4.2 Installation Notes for Microsoft Windows

System Requirements

SoftwareSystem Configurations

This installation requires Windows Installer 2.0 to be on your machine, or an Internet connection for it to be automatically downloaded. For more details, see the troubleshooting note about Windows Installer 2.0.

Hardware - Intel and 100% compatible processors are supported. A Pentium 166MHz or faster processor with at least 32 megabytes of physical RAM is required to run graphically based applications. At least 48 megabytes of RAM is recommended for applets running within a browser using the Java Plug-in. Running with less memory may cause disk swapping which has a severe effect on performance. Very large programs may require more RAM for adequate performance.

For the amount of disk space required, see Windows Disk Space Requirements.


Note: Trying to install the Java 2 Runtime Environment on a non-supported version of Microsoft Windows or on a machine that doesn't have a sufficiently up-to-date Service Pack will cause the installer to generate this warning: "We recommend that you do not install this Java Platform for the following reasons: This Java Platform does not support the operating system or operating-system service pack on this machine."


Installation Instructions

Windows Installation (IFTW) and Java Update FAQProxy Settings and Authentication

Note: For any text on this page containing the following notation, you must substitute the appropriate update version number for the notation.
For example, if you are downloading the installer for update 1.4.2_01, the following file name:
would become:

1. If choosing "Windows Offline Installation", download and check the download file size

After clicking the JRE "Download" link for the "Windows Offline Installation" (info) , a dialog box pops up -- choose the following option:
  • Save - This saves the downloaded file without installing it. Check that you have downloaded the entire file by comparing the size of the file you downloaded with the expected size shown on the download page:


    This file contains everything needed to install the Java 2 Runtime Environment, including the installer and character conversion classes and support for locales other than the US English locale.

2. If 1.4.2 Beta is installed, uninstall it.

Use the Microsoft Windows Add/Remove Programs utility, accessible from the Control Panel (Start -> Settings -> Control Panel).

3. Run the installer
Note - you must have administrative permissions in order to install the Java 2 Runtime Environment on Microsoft Windows 2000 and XP.

The download page provides the following two choices of installation. Continue based on your choice.

a. Windows Installation (info) - After clicking the "Download" link for the JRE, a dialog box pops up -- choose the following option:

  • Open - This starts a small program which then prompts you for more information about what you want to install.


This option starts the installation process by downloading and executing the file j2re-1_4_2_<version>-windows-i586-iftw.exe, which prompts you through the steps to download and install only the features you request. (The letters " iftw" mean "install from the web".)

b. Windows Offline Installation (info) - Run the file downloaded in step 1 by double-clicking on the installer's icon. Then follow the instructions the installer provides. When done with the installation, you can delete the downloaded file to recover disk space.

With either choice, the installer may ask you to reboot your computer

4. If you want to run Netscape 7.x or Mozilla 1.x with Java Plug-in, do this:


  • Exit the Netscape 7.x or Mozilla 1.x browser and all of its "objects" (Messenger, Composer ...);
  • If the Quick Launch feature is enabled, disable it;
  • Then restart Netscape 7.x or Mozilla 1.x.

The installation process also installs Java Web Start. Look for a Java Web Start icon on your desktop. There will also be an entry for Java Web Start in the Start -> Programs menu.

Java Web Start
  • Compatibility: The release of Java Web Start that comes with this J2RE can be run on J2RE 1.2.2 or later. It will not work with J2RE 1.1.x or earlier.
  • Upgrading from Previous Versions: If you have a previous release of Java Web Start, do not uninstall it. Uninstalling it will cause the download cache to be cleared, and all previously installed Java Web Start application data will have to be downloaded again. This new release will overwrite previous installations and automatically update browsers to use this new release. The configuration files and program files folder used by Java Web Start have changed, but all your settings will remain intact after the upgrade, since Java Web Start will translate your settings to the new form.
  • Uninstalling 1.4.2 SDK/JRE: The only way to uninstall Java Web Start 1.4.2 is to uninstall the 1.4.2 SDK/JRE. But note that doing so will remove the 1.4.2 Java Web Start cache, which stores the Java Web Start application data. Uninstalling the SDK/JRE will not, however, remove the cache for previous releases of Java Web Start (1.0.1 and 1.2). Previous releases have separate uninstallers for Java Web Start.
  • Using Java Web Start with Netscape 6.x/7.x: For Netscape 6.x/7.x users, setup the Java Web Start MIME type (JNLP) in the Edit->Preferences->Navigator->Helper Applications section. The file extension is jnlp; MIME Type is application/x-java-jnlp-file. It should be handled by the javaws executable file in your Java Web Start directory. Also note that, due to a problem with the JavaScript in Netscape 6.x/7.x, you must use the non-JavaScript version of the demos page
Silent Install - To install the Java 2 Runtime Environment non-interactively, which is useful for installing on multiple machines, use Silent Install Instructions.
Launch Applications Directly - If you want to use the Invocation API to launch an application directly rather than using the Java application launcher, please see Location of VM Library Files (jvm.dll).
troubleshooting section