How to change java version on windows

In this article, I will show you how to install multiple Java versions on Windows and how to change the Java version on the command line:

To enable these Java version change commands on your system as well, follow this step-by-step guide.

Let’s go…

Step 1: Installing Multiple Java Versions

Installing multiple Java versions in parallel is incredibly easy in Windows. You can download and run the installer for each version, which automatically installs the versions in separate directories.

Download Sources

• Java SE 1.1 – You can no longer install this version on 64-bit Windows.
• Java SE 1.2 – Installed to C:jdk1.2.2 and C:Program Files (x86)JavaSoftJRE1.2 by default – I recommend changing this to C:Program Files (x86)Javajdk1.2.2 and C:Program Files (x86)Javajre1.2.2 for the sake of clarity.
• Java SE 1.3 – Installed to C:jdk1.3.1_28 by default – I recommend changing this to C:Program Files (x86)Javajdk1.3.1_28.
• Java SE 1.4 – Installed to C:j2sdk1.4.2_19 by default – I recommend changing this to C:Program Files (x86)Javajdk1.4.2_19.

Starting with the following versions, you don’t need to change the default installation directories:

• Java SE 5
• Java SE 6
• Java SE 7
• Java SE 8
• Java SE 9 / OpenJDK 9
• Java SE 10 / OpenJDK 10 (→ The most important new features in Java 10)

Attention – you may use the following Oracle distributions only for private purposes and development:

• Java SE 11 / OpenJDK 11 (→ The most important new features in Java 11)
• Java SE 12 / OpenJDK 12 (→ The most important new features in Java 12)
• Java SE 13 / OpenJDK 13 (→ The most important new features in Java 13)
• Java SE 14 / OpenJDK 14 (→ The most important new features in Java 14)
• Java SE 15 / OpenJDK 15 (→ The most important new features in Java 15)
• Java SE 16 / OpenJDK 16 (→ The most important new features in Java 16)
• Java SE 17 / OpenJDK 17 (→ The most important new features in Java 17)
• Java SE 18 / OpenJDK 18 (→ The most important new features in Java 18)
• Java SE 19 / OpenJDK 19 (→ The most important new features in Java 19)

The following version is currently an early access build. You should use it only for testing purposes:

• JDK 20 Early-Access Build (→ The most important new features in Java 20)

Step 2: Define Java Environment Variables

The following two environment variables decide which Java version an application uses:

• JAVA_HOME – many start scripts use this variable.
• Path – is used when running a Java binary (such as java and javac) from the console.

These variables should always point to the same Java installation to avoid inconsistencies. Some programs, such as Eclipse, define the Java version in a separate configuration file (for Eclipse, for example, this is the entry «-vm» in the eclipse.ini file).

Manually Setting the Java Environment Variables

The Java installers create various environment variables, which you need to clean up first (see below). The fastest way to change the environment variables is to press the Windows key and type «env» – Windows then offers «Edit the system environment variables» as a search result:

At this point, you can press «Enter» to open the system properties:

Click on «Environment Variables…» and the following window opens:

As the default version, I recommend the current release version, Java 19. Accordingly, you should make the following settings:

• The top list («User variables») should not contain any Java-related entries.
• The lower list («System variables») should contain an entry «JAVA_HOME = C:Program FilesJavajdk-19». If this entry does not exist, you can add it with «New…». If it exists but points to another directory, you can change it with «Edit…».
• Delete the following entries under «Path» (if they exist):
  • C:ProgramDataOracleJavajavapath
  • C:Program Files (x86)Common FilesOracleJavajavapath
• Insert the following entry instead:
  • %JAVA_HOME%bin

The entry should then look like the following (the other entries in the list will probably look different for you since you have other applications installed than I do):

The last entry ensures that Path and JAVA_HOME are automatically consistent.

Attention: this only works for the default setting configured here. If you change JAVA_HOME via the command line, you have to adjust Path accordingly. But don’t worry – the scripts you can download in the next step will do that automatically.

How to Check Your Java Version on Windows

Now open a command line to check the settings with the following commands:

echo %JAVA_HOME%
java -version
Code language: plaintext (plaintext)

Here’s what you should see:

Step 3: Install the Scripts to Change the Java Version

To change the Java version on the command line, I have prepared some batch files that you can copy to your system. Here is the link: scripts-up-to-java20-v2.zip

The ZIP file contains scripts named java20.bat, java19.bat, java18.bat, etc., for all Java versions, plus some common scripts starting with «javaX». I suggest you unpack the scripts to C:Program FilesJavascripts.

The scripts look like this:

java19.bat:

@echo off
call javaX "Java 19"
Code language: DOS .bat (dos)

javaX.bat:

@echo off
call javaX-JAVA_HOME %1
set Path=%JAVA_HOME%bin;%Path%
echo %~1 activated.




  


                       
  



Code language: DOS .bat (dos)

javaX-JAVA_HOME.bat:

@echo off
if %1 == "Java 1.2" set JAVA_HOME=C:Program Files (x86)Javajdk1.2.2
if %1 == "Java 1.3" set JAVA_HOME=C:Program Files (x86)Javajdk1.3.1_28
...
if %1 == "Java 19" set JAVA_HOME=C:Program FilesJavajdk-19
if %1 == "Java 20" set JAVA_HOME=C:Program FilesJavajdk-20
Code language: DOS .bat (dos)

The scripts update the JAVA_HOME environment variable and insert the bin directory at the beginning of the Path variable. That makes it the first directory to be searched for the corresponding executable when you run Java commands such as java or javac.

(The Path variable gets longer with each change. Do not worry about it. This only affects the currently opened command line.)

Step 4: Add the Script Directory to the Path

To be able to call the scripts from anywhere, you have to add the directory to the «Path» environment variable (just like you did with «%JAVA_HOME%bin» in the second step):

If you have installed the latest releases of all Java versions, you can use the scripts without any further adjustments. Open a new command line and enter, e.g., the following commands:

If one of the commands does not activate the expected Java version, please check if the path in the javaX-JAVA_HOME.bat file corresponds to the installation path of the Java version you want to activate.

Temporary, Permanent, and System-Wide Java Version Changes

The commands presented up to this point only affect the currently opened command line. As soon as you open another command line, the default version defined in step 2 is active again (Java 19, if you have not changed anything).

That is why there are not one but three scripts for each Java version:

• java<version>: Activates the Java version in the current command line.
• java<version>-user: Sets the Java version as the default version for your user account.
• java<version>-system: Sets the Java version as the default version for the entire system-

The -user variants of the scripts additionally set the JAVA_HOME environment variable with the setx command, permanently writing the change to the registry:

java19-user.bat:

@echo off
call javaX-user "Java 19"
Code language: DOS .bat (dos)

javaX-user.bat:

@echo off
call javaX-JAVA_HOME %1
setx JAVA_HOME "%JAVA_HOME%"
set Path=%JAVA_HOME%bin;%Path%
echo %~1 activated as user default.




  


                       
  



Code language: DOS .bat (dos)

The -system variants also specify the /M parameter in the setx command. This sets the system-wide environment variable instead of the user-specific one:

java19-system.bat:

@echo off
call javaX-system "Java 19"
Code language: DOS .bat (dos)

javaX-system.bat:

@echo off
call javaX-JAVA_HOME %1
setx JAVA_HOME "%JAVA_HOME%" /M
set Path=%JAVA_HOME%bin;%Path%
echo %~1 activated as system-wide default.
Code language: DOS .bat (dos)

Attention: To set the system-wide Java version, you must open the command line as an administrator. Otherwise, you will get the error message «ERROR: Access to the registry path is denied.

What You Should Do Next…

I hope you were able to follow the instructions well and that the commands work for you.

Now I would like to hear from you:

Were you able to follow the steps well – or do you have unanswered questions?

Either way, let me know by leaving a comment below.

For Java applications, i.e. programs that are delivered (usually) as .jar files and started with java -jar xxx.jar or via a shortcut that does the same, the JRE that will be launched will be the first one found on the PATH.

If you installed a JRE or JDK, the likely places to find the .exes are below directories like C:Program FilesJavaSoftJREx.y.z. However, I’ve found some «out of the box» Windows installations to (also?) have copies of java.exe and javaw.exe in C:winntsystem32 (NT and 2000) or C:windowssystem (Windows 95, 98). This is usually a pretty elderly version of Java: 1.3, maybe? You’ll want to do java -version in a command window to check that you’re not running some antiquated version of Java.

You can of course override the PATH setting or even do without it by explicitly stating the path to java.exe / javaw.exe in your command line or shortcut definition.

If you’re running applets from the browser, or possibly also Java Web Start applications (they look like applications insofar as they have their own window, but you start them from the browser), the choice of JRE is determined by a set of registry settings:

Key: HKEY_LOCAL_MACHINESoftwareJavaSoftJava Runtime Environment
Name: CurrentVersion
Value: (e.g.) 1.3

More registry keys are created using this scheme:

(e.g.) 
HKEY_LOCAL_MACHINESoftwareJavaSoftJava Runtime Environment1.3   
HKEY_LOCAL_MACHINESoftwareJavaSoftJava Runtime Environment1.3.1

i.e. one for the major and one including the minor version number. Each of these keys has values like these (examples shown):

JavaHome    : C:program FilesJavaSoftJRE1.3.1
RuntimeLib  : C:Program FilesJavaSoftJRE1.3.1binhotspotjvm.dll
MicroVersion: 1

… and your browser will look to these settings to determine which JRE to fire up.

Since Java versions are changing pretty frequently, there’s now a «wizard» called the «Java Control Panel» for manually switching your browser’s Java version. This works for IE, Firefox and probably others like Opera and Chrome as well: It’s the ‘Java’ applet in Windows’ System Settings app. You get to pick any one of the installed JREs. I believe that wizard fiddles with those registry entries.

If you’re like me and have «uninstalled» old Java versions by simply wiping out directories, you’ll find these «ghosts» among the choices too; so make sure the JRE you choose corresponds to an intact Java installation!

Some other answers are recommending setting the environment variable JAVA_HOME. This is meanwhile outdated advice. Sun came to realize, around Java 2, that this environment setting is

1. unreliable, as users often set it incorrectly, and
2. unnecessary, as it’s easy enough for the runtime to find the Java library directories, knowing they’re in a fixed path relative to the path from which java.exe or javaw.exe was launched.

There’s hardly any modern Java software left that needs or respects the JAVA_HOME environment variable.

More Information:

• http://java.sun.com/j2se/1.3/runtime_win32.html
• http://www.rgagnon.com/javadetails/java-0604.html

…and some useful information on multi-version support:

• http://www.rgagnon.com/javadetails/java-0604.html

>java -version
java version "1.8.0_66"
Java(TM) SE Runtime Environment (build 1.8.0_66-b18)
Java HotSpot(TM) 64-Bit Server VM (build 25.66-b18, mixed mode)

PATH=C:ProgramDataOracleJavajavapath; ... C:Program FilesJavajdk1.6.0_45bin

C:Program FilesJavajdk1.7.0_75

%JAVA_HOME%bin

C:Program Files (x86)Common FilesOracleJavajavapath;

...;%JAVA_HOME%bin;

Tags:

Java

Windows 10

Java is a high-level, robust, object-oriented, and secure programming language that was developed in the year 1995 by Sun Microsystems (which is now part of Oracle group), and James Gosling is known as the father of Java.  It is a general-purpose programming language intended to let programmers write once, and run anywhere, meaning that compiled Java code is compatible to run on all platforms that support Java without the need to recompile which is a major advantage.

Java Update

Java Update is a feature that keeps your windows computer up to date with the latest Java releases. You can use Java’s update feature to manually force an available update on windows. But, when you have auto update enabled, your system periodically checks for new versions of Java and updates it automatically.

Auto Update in Java

We can get the auto-update feature in Java

First, you need to check whether the windows check for update automatically you can do this by following the steps: 

1.  Open the start by clicking on the windows logo on the bottom left side of the screen, and the start menu will pop up.
2.  Now type configures Java and clicks on configure Java option from the list of matching programs, this will open Java control panel.
3.  Once Java Control Panel is launched click on the update tab to access settings.
4.  Select the Check for Updates Automatically check box for enabling Java updates to check for updates automatically.

Now, whenever an update is available you will receive a notification asking your permission to download the update, and a tooltip balloon appears on your Windows desktop. To install the new update, click on the notification dialog.

Now an Update Available dialog appears. To start the installation, click Update. Otherwise, you can click Later to install the update at a later time. When the installation is complete a dialog appears where you can click Finish to complete the installation.

Using the Update Schedule, you can change the frequency for updates accordingly: daily, weekly, or monthly (default). To do this follow the given steps:

1.  From the Java Control panel click on the Update tab, then select Advanced, now the Automatic Update Advanced Settings dialog will appear.
2.  Here you can change the frequency and the date and time for the Java Update, finally click OK.

 Java Update scheduler will check for newer Java updates and notify you at the scheduled frequency.

Java Manual Update

1. Open the Start option by clicking the Windows logo in the bottom-left corner of the screen. The Start menu will pop up.

2. Type in configure java in the search box and searches for matching programs will be displayed.

3. Click on configure java option from the list of matching programs and the Java Control Panel will open.

4. Click on the update option in the Java control panel and then click on the Update now option at the bottom-right corner of the window and this initiates the Java to look for new updates.

5.  If Java finds an available update, follow any on-screen prompts that appear to confirm the update, then allow your computer to install the latest version of Java.

You cannot update to a new version of Java if you receive a dialog box saying that you are already running the latest version of Java.

 Finally, if you are not sure about the Java version then go to the official link to update to the latest version.