Java Runtime Environment
If you are not sure whether you have Oracle's JDK or JRE installed correctly, please confirm by doing the following:
- Run a complete directory search (using the 'All File and Folders' option if available) on your drives for the occurrence of 'jdk' in the filename.
- To confirm correct JRE installation , run a complete directory search (using the 'All File and Folders' option if available) on your drives for the occurrence of 'jre' in the filename.
- If your results retrieve a folder with the name 'jdk' immediately followed by a series of version numbers (for example, jdk1.5.0_06), then your Sun JDK has been installed. You should double-check the contents of this folder to ensure that the installation files are intact. If you are unsure about this, proceed to step 3 to re-install the Sun JDK. Otherwise, proceed to step 3 to check that your JAVA_HOME environment variable has been set correctly.
- If your results retrieve a folder with the name 'jre' immediately followed by a version number (for example, jre6), then your Sun JRE has been installed. You should double-check the contents of this folder to ensure that the installation files are intact. If you are unsure about this, proceed to step 4 to re-install the Sun JRE. Otherwise, proceed to step 4 to check that your JRE_HOME environment variable has been set correctly.
- If you do not retrieve results as explained above, then it is highly likely that your Sun JDK or JRE has not been installed.
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3. To install the Sun JDK, follow these instructions:
- Go to the Java Sun download page.
- Download the JDK version 1.6 or 1.7. will work with either one.
- When the download has finished, run the Java installer. At one point, you will be asked to choose a directory to install to. Copy or write this directory down for use later.
- Check that the JAVA_HOME environment variable has been set correctly.
- Open the 'Start' menu, choose 'Run', type cmd in the 'Run' dialog box and click the 'OK' button.
- In the command prompt window, type echo %JAVA_HOME% and then press Enter.
- View the result:
- If a directory path is display that looks similar to one of the following examples, with the letters 'jdk' immediately preceding a series of version numbers, and this path matches the location where you installed the Sun JDK in step 3c, then your Sun JDK has been successfully installed and your JAVA_HOME environment variable has been set correctly. ''Examples of typical JAVA_HOME environment variable values'':
- C:\Program Files\Java\jdk1.6.0_17
- C:\Progra~1\Java\jdk1.6.0_17
- C:\Java\jdk1.6.0_17
- C:\jdk1.6.0_17
- If nothing is displayed or you do not see 'jdk' immediately followed by a series of version numbers (like one of the examples above), then you need to set the JAVA_HOME environment variable. Please follow these instructions to set your JAVA_HOME environment to the directory you where you have just installed the JDK. By default, this directory is under C:\Program Files\Java for a 32 bit Windows System. You will find it under c:\Program Files (x64) on a 64 bit Windows system.
- 4. To install the Sun JRE, follow these instructions:
- Go to the Java Sun download page.
- Download the JRE version 6 or 7. will work with either one.
- When the download has finished, run the Java installer. At one point, you will be asked to choose a directory to install to. Copy or write this directory down for use later.
- Check that the JRE_HOME environment variable has been set correctly.
- Open the 'Start' menu, choose 'Run', type cmd in the 'Run' dialog box and click the 'OK' button.
- In the command prompt window, type echo %JRE_HOME% and then press Enter.
- View the result:
- If a directory path is display that looks similar to one of the following examples, with the letters 'jre' immediately preceding a series of version numbers, and this path matches the location where you installed the Sun JRE in step 3c, then your Sun JDK has been successfully installed and your JAVA_HOME environment variable has been set correctly. ''Examples of typical JAVA_HOME environment variable values'':
- C:\Program Files\Java\jdk1.6.0_17
- C:\Progra~1\Java\jdk1.6.0_17
- C:\Java\jdk1.6.0_17
- C:\jdk1.6.0_17
- If nothing is displayed or you do not see 'jdk' immediately followed by a series of version numbers (like one of the examples above), then you need to set the JAVA_HOME environment variable. Please follow these instructions to set your JAVA_HOME environment variable to the directory you where you have just installed the JDK. By default, this directory is under C:\Program Files\Java for a 32 bit Windows System. You will find it under c:\Program Files (x64) on a 64 bit Windows system.
Locate the JDK or JRE Installation Directory
If you already know the installation path for the Java or Software Development Kit, go to Step 2 below. Otherwise, find the installation path by following these instructions:
- Unless you changed the installation path for the Java Development Kit during installation, it will be in a directory under C:\Program Files\Java. Using Explorer, open the directory C:\Program Files\Java.
- Inside that path will be one or more subdirectories such as jdk1.5.0_08. If you have just installed the Java Development Kit, it will be installed to the newest directory, which you can find by sorting by date. For example, it may be installed in C:\Program Files\Java\jdk1.5.0_08. This is the installation path.
Set the JAVA_HOME Environment Variable
Once you have identified the JDK installation path:
- Right-click the My Computer icon on your desktop and select 'Properties'.
- Click the 'Advanced' tab.
- Click the 'Environment Variables' button.
- Under 'System Variables', click 'New'.
- Enter the variable name as JAVA_HOME.
- Enter the variable value as the installation path for the Java Development Kit.
- Click 'OK'.
- Click 'Apply Changes'.
Return to installation instructions.