Installation Notes

System Requirements

System Configurations

Windows Installer 2.0

Note: Trying to install the J2SE 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 Online Installation (IFTW) and Java Update FAQ

Java Update


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 1.5.0_01, the following file name: jre-1_5_0_<version>-windows-i586.exe

would become: jre-1_5_0_01-windows-i586.exe

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

After clicking the JRE "Download" link for the "Windows Offline Installation", 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:
  • jre-1_5_0_<version>-windows-i586.exe

    This file contains everything needed to install the J2SE Runtime Environment, including the installer and character conversion classes and support for locales other than the US English locale.

2. Run the installer

Notes - (1) You must have administrative permissions in order to install the J2SE Runtime Environment on Microsoft Windows 2000 and XP. (2) For users doing this installation on non-Western 32-bit machines, select "Custom" for Setup Type. Then, in Custom Setup under feature 2 ("Support for Additional Languages"), select "This feature will be installed on local hard drive."

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

a. Windows Online Installation - 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 jre-1_5_0_<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 - 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

3. 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.

Java Web Start

  • Compatibility: The release of Java Web Start that comes with this JRE can be run on JRE 1.2.2 or later. It will not work with JRE 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 5.0 JDK/JRE: (1) The only way to uninstall Java Web Start 5.0 is to uninstall the 5.0 JDK/JRE. But note that doing so will remove the 5.0 Java Web Start cache, which stores the Java Web Start application data. Uninstalling the JDK/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. (2) You may see a misleading message if you do the following: first download and cache a Java Web Start (JNLP) application with the 5.x JDK/JRE; next remove the 5.x JDK/JRE using "Add or Remove Programs" from the Windows Control Panel; then try to remove the Java Web Start application using "Add or Remove Programs." This misleading message can occur as follows: When you select to remove the application, you will see an "Uninstaller Error" dialog saying "An error occurred while trying to remove Java-Application: <name> App. It may have already been uninstalled. Would you like to remove Java-Application: <name> App from the Add or Remove program list?" If you say yes to this, then you will see another "Uninstaller Error" dialog saying "You do not have sufficient access to remove Java-Application: <name> App from the Add or Remove Program list. Please contact your system administrator." This is the misleading message. It implies that the problem is due to privileges. It is not. The problem is that you have already removed the Java Web Start application when you removed the 5.x JDK/JRE, but this is not reflected in the "Add or Remove Programs" dialog until it is refreshed by pressing F5 or it is closed and reopened. To avoid seeing this misleading message, either press F5 or close and reopen the dialog. Any Java Web Start application that was downloaded and cached with the 5.x version of the JDK/JRE will no longer appear in the list of currently installed programs.
  • 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 J2SE Runtime Environment non-interactively, which is useful for installing on multiple machines, use the following instructions:

JRE Deployment for System Administrators - The JRE can be distributed to intranet users by hosting the .msi file on an internal website and asking users to launch the installer through msiexec. The other option is to install the JRE through Active Directory. The instructions for these are available in the "Intranet Deployment" section of JRE Intranet Deployment.

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