System Requirements

Software - Java 2 SDK Standard Edition, 1.4.2 is supported on i586 Intel and 100% compatible platforms running Microsoft Windows. For a list of supported operating systems and desktop managers, see System Configurations.

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.

Installation Instructions

In this procedure, you will run the self-installing executable to unpack and install the Java 2 SDK software bundle. As part of the Java 2 SDK, this installation includes the Java Plug-in and Java Web Start, as well as an option to include the public Java 2 Runtime Environment. (The Java 2 SDK also contains a private J2RE for use only by its tools.)
For issues related to Windows Installation (IFTW) and Java Update, see the Windows Installation (IFTW) and Java Update FAQ. See this note on Proxy Settings and Authentication.

Print or bookmark these instructions - After the Java 2 SDK software has been installed, you may be asked to reboot your system. To continue using these instructions after rebooting, either print this page now, bookmark it now, or use your Web browser's history function to get back to this page.

Troubleshooting - If you have any difficulties, see the Troubleshooting section at the end of this document or submit a bug report for your installation problem.
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:

j2sdk-1_4_2_-windows-i586.exe

would become:

j2sdk-1_4_2_01-windows-i586.exe
1.
 Check the download file size (Optional)

If you save the self-installing executable to disk without running it from the download page at the web site, notice that its byte size is provided on the download page. Once the download has completed, check that you have downloaded the full, uncorrupted software file.

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 Java 2 SDK installer

Note - you must have administrative permissions in order to install the Java 2 SDK on Microsoft Windows 2000 and XP. The file j2sdk-1_4_2_-windows-i586-i.exe is the Java 2 SDK installer. If you downloaded it instead of running it directly from the web site, double-click on the installer's icon. Then follow the instructions the installer provides. The installer may ask you to reboot your computer. When done with the installation, you can delete the download file to recover disk space.

Note -- Trying to install the Java 2 SDK 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." See the system requirements above for information on supported configurations of Microsoft Windows.

Installed Directory Tree
The Java 2 SDK has the directory structure shown below.

j2sdk1.4.2_ ____________________|___________________ | | | | | | | | | | | | | bin lib | demo | | | | LICENSE | | | jre | | COPYRIGHT | __|__ | README.txt include | | readme.html bin lib

In addition, the Java Plug-in and Java Web Start will automatically be installed. 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 SDK/JRE can be run on SDK/JRE 1.2.2 or later. It will not work with SDK/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 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

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

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

5. Update the PATH variable (Optional)

You can run the Java 2 SDK without setting the PATH variable, or you can optionally set it as a convenience. Should I set the PATH variable?
Set the PATH variable if you want to be able to conveniently run the Java 2 SDK executables (javac.exe, java.exe, javadoc.exe, etc.) from any directory without having to type the full path of the command. If you don't set the PATH variable, you need to specify the full path to the executable every time you run it, such as:

C:> \j2sdk1.4.2_\bin\javac MyClass.java

It's useful to set the PATH permanently so it will persist after rebooting. How do I set the PATH permanently?
To set the PATH permanently, add the full path of the j2sdk1.4.2_\bin directory to the PATH variable. Typically this full path looks something like C:\j2sdk1.4.2_\bin. Set the PATH as follows, according to whether you are on Microsoft Windows NT or 98/2000/ME.
Microsoft Windows NT, 2000, and XP - To set the PATH permanently:

1. Choose Start, Settings, Control Panel, and double-click System. On Microsoft Windows NT, select the Environment tab; on Microsoft Windows 2000 select the Advanced tab and then Environment Variables. Look for "Path" in the User Variables and System Variables. If you're not sure where to add the path, add it to the right end of the "Path" in the User Variables. A typical value for PATH is:
   
   

   C:\j2sdk1.4.2_\bin 
   

   Capitalization doesn't matter. Click "Set", "OK" or "Apply". The PATH can be a series of directories separated by semi-colons (;). Microsoft Windows looks for programs in the PATH directories in order, from left to right. You should only have one bin directory for a Java SDK in the path at a time (those following the first are ignored), so if one is already present, you can update it to j2sdk1.4.2_\bin.
   
   
   
   
2. The new path takes effect in each new Command Prompt window you open after setting the PATH variable.

Microsoft Windows 98 - To set the PATH permanently, open the AUTOEXEC.BAT file and add or change the PATH statement as follows:

1. Start the system editor. Choose "Start", "Run" and enter sysedit, then click OK. The system editor starts up with several windows showing. Go to the window that is displaying AUTOEXEC.BAT
   
2. Look for the PATH statement. (If you don't have one, add one.) If you're not sure where to add the path, add it to the right end of the PATH. For example, in the following PATH statement, we have added the bin directory at the right end:
   
   
   

   PATH C:\WINDOWS;C:\WINDOWS\COMMAND;C:\J2SDK1.4.2_\BIN 
   

   Capitalization doesn't matter. The PATH can be a series of directories separated by semi-colons (;). Microsoft Windows searches for programs in the PATH directories in order, from left to right. You should only have one bin directory for a Java SDK in the path at a time (those following the first are ignored), so if one is already present, you can update it to j2sdk1.4.2_.
   
   
   
3. To make the path take effect in the current Command Prompt window, execute the following:
   
   

   C:> c:\autoexec.bat
   

   To find out the current value of your PATH, to see if it took effect, at the command prompt, type:
   
   

   C:> path
   

   
   
   

Microsoft Windows ME - To set the PATH permanently:

From the start menu, choose programs, accessories, system tools, and system information. This brings up a window titled "Microsoft Help and Support". From here, choose the tools menu, then select the system configuration utility. Click the environment tab, select PATH and press the edit button. Now add the SDK to your path as described in step b above. After you've added the location of the SDK to your PATH, save the changes and reboot your machine when prompted.

6. Start using the Java 2 SDK!

Your computer system should now be ready to use the Java 2 SDK. In this step, you'll run some simple commands to make sure it is working properly. If you are new to developing and running programs in the Java programming language, see The Java Tutorial online for some guidance. Note especially the tutorial trails under the heading Trails Covering the Basics.
You can also download the Java 2 SDK documentation from the Java 2 SDK download page..

Uninstalling the Java 2 SDK
If you should ever want to uninstall the Java 2 SDK, use the "Add/Remove Programs" utility in the Microsoft Windows Control Panel. As an alternative method, if you still have the original installation program that you used to install the Java 2 SDK, you can double click on it to launch an uninstall program.

Location of VM Library Files (jvm.dll)

If you use the Invocation API to launch an application directly rather than using the Java application launcher, be sure to use the correct paths to invoke the Java HotSpot Client Virtual Machine (VM) or Java HotSpot Server VM, as desired. The path within the Java SDK to the Java HotSpot Client VM is:

jre/bin/client/jvm.dll (on x86)

The path to the Java HotSpot Server VM is:

jre/bin/server/jvm.dll (on x86)
jre/bin/server/jvm.dll (on IA64)

The corresponding locations in the Java 2 Runtime Environment begin with j2re1.4.2 instead of jre. The Exact VM and Classic VM are no longer part of the Java 2 SDK, and existing code that uses the Invocation API to launch an application based on old paths to the Exact or Classic VMs will not work.

Troubleshooting the Installation

Below are some tips for working around problems that are sometimes seen during or following an installation. For more troubleshooting information, see the Java FAQ.

• If Netscape 6.2.x fails to launch a 1.4.2 applet and you installed 1.4.2 after you installed 1.4 (and both are still installed), do either of the following:
  
  
  
  • Uninstall 1.4 before you install 1.4.2;
  • Before you install 1.4.2, open the 1.4 Java Plug-in Control Panel, select the Browser tab, and deselect Netscape 6.
  
  
  
  
• If you see the following error message about Microsoft Windows Installer 2.0:
  
  

  An error occured while downloading the file
  http://www.installengine.com/Msiengine20/instmsiw.exe.
  What would you like to do?
  

  When installing version 1.4.2 of Java 2 Runtime Environment or Java 2 SDK (using the default minimized download rather than the single executable), InstallShield requires Microsoft Windows Installer 2.0 to be on your machine; if it is not found (or an older version is found), then InstallShield automatically tries to download Microsoft Windows Installer 2.0. If your machine is not on the Internet or is behind an authenticated proxy, the installation will fail at that point. To proceed, simply use the Windows Offline Installer from the download page. Microsoft Windows Installer 2.0 is included in this download.
  Alternatively, you can manually download Microsoft Windows Installer 2.0 by going to microsoft.com and searching for "Windows Installer 2.0".
  Version 2.0 of Microsoft Windows Installer is included in Windows XP and Windows 2000 Service Pack 3, but not in earlier versions of Windows.
  To see which version of Microsoft Windows Installer is installed, do the following:
  
  
  
  
  1. Locate the file MSI.DLL. (Usually located in C:\WINNT\SYSTEM32 )
  2. Select the file and right-click on it.
  3. Choose "Properties" and click on the "Version" tab.
  
  
  
  
• If you get an error about one of the following during InstallShield setup:
  
  
  
  • Error extracting support files. A typical error message is An Installation support file could not be installed. The filename, directory or volume label syntax is incorrect.
  • Error installing Ikernel.exe (0x any number)
  • Access is denied
  • Error loading Type Library/DLL
  These errors could be caused by a known problem with InstallShield. See the InstallShield web site for a discussion of this problem with possible solutions: http://support.installshield.com/kb/view.asp?pcode=ALL&articleid=Q104985
  
  
  
• If you see the following error message:
  
  

  The InstallShield engine (iKernel.exe) could not be launched.
  Error loading type library/DLL
  

  This message probably indicates that system file Stdole32.tlb is missing from your computer. You can obtain this file from the Microsoft web site. For Microsoft Windows 98 platforms, for example, this file is included in the DCOM98 product.
  
  
  
• If you see the following error message on Microsoft Windows 2000
  
  

  config.nt. The system file is not suitable for running MS-DOS 
  and Microsoft Windows Applications.
  

  it indicates a problem with the %SystemRoot%\System32\COMMAND.COM file that has been seen on some installations of Microsoft Windows 2000. If you encounter this error message when you try to launch the installer, consult the Microsoft web site at:
  
  

  http://support.microsoft.com/support/kb/articles/Q142/2/71.asp
  

  for information about resolving the problem.
  
  
  
• If you see the following error message
  
  

  corrupt cabinet file
  

  then the file you have downloaded is corrupted. (A cabinet file contains compressed application, data, resource and DLL files.) Check its file size against the expected file size listed in these instructions. If they don't match, try downloading the bundle again.
  
  
  
• If you see the following error message
  
  

  System Error during Decompression
  

  then you might not have enough space on the disk that contains your TEMP directory.
  
  
  
• If you see the following error message
  
  

  This program cannot be run in DOS mode.
  

  then do the following:
  
  
  
  1. Open the MS-DOS shell or Command Prompt window
     
  2. Right-click on the title bar
     
  3. Select Properties
  4. Choose the Program tab
  5. Push the Advanced button
  6. Make sure the item "Prevent MS-DOS-based programs from detecting Windows" is unchecked
  7. Select OK
  8. Select OK again
  9. Exit the MS-DOS shell
  10. Restart your computer.
  
  
  
  
• Private vs. public J2RE - Installing the Java 2 SDK installs a private Java 2 Runtime Environment and optionally a public copy. The private J2RE is required to run the tools included with the Java 2 SDK. It has no registry settings and is contained entirely in a jre directory (typically at C:\Program Files\j2sdk1.4.2\jre) whose location is known only to the SDK. On the other hand, the public J2RE can be used by other Java applications, is contained outside the SDK (typically at C:\Program Files\Java\j2re1.4.2), is registered with the Windows registry (at HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft), can be removed using Add/Remove Programs, might or might not be registered with browsers, and might or might not have java.exe copied to the Windows system directory (making it the default system Java platform or not).
  
• Creating source files in Notepad - In Microsoft Windows, when you create a new file in Microsoft Notepad and then save it for the first time, Notepad normally adds the .txt extension to the filename. Therefore, a file you name Test.java is saved as Test.java.txt. It's important to note that you cannot see the .txt extension unless you turn on the viewing of file extensions (in Microsoft Windows Explorer, uncheck "Hide file extensions for known file types" under Folder Options). To prevent the .txt extension, enclose the filename in quotation marks, such as "Test.java", when typing it into the Save As dialog box. On the other hand, Microsoft WordPad does not add a file extension if you provide one -- you must save the file as "Text Document".
  
  
• Choosing an installation path containing characters that are not part of the system code page - On Windows 2000, XP, and 2003, it is possible to name directories using characters that are not part of the system locale's code page. If such a directory is part of the installation path, then error 1722 occurs, and installation is not completed. To prevent this problem, make sure that the user and system locales are identical, and that the installation path only contains characters that are part of the system locale's code page. User and system locales can be set in the Regional Options or Regional Settings control panel.
  The associated bug number is 4895647.