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Windows can not find javaw.exe [duplicate]

I am trying to add C:\xampp\php to my system PATH environment variable in Windows.
I have already added it using the Environment Variables dialog box.
But when I type into my console:
C:\>path
it doesn't show the new C:\xampp\php directory:
PATH=D:\Program Files\Autodesk\Maya2008\bin;C:\Ruby192\bin;C:\WINDOWS\system32;C:\WINDOWS;
C:\WINDOWS\System32\Wbem;C:\PROGRA~1\DISKEE~2\DISKEE~1\;c:\Program Files\Microsoft SQL
Server\90\Tools\binn\;C:\Program Files\QuickTime\QTSystem\;D:\Program Files\TortoiseSVN\bin
;D:\Program Files\Bazaar;C:\Program Files\Android\android-sdk\tools;D:\Program Files\
Microsoft Visual Studio\Common\Tools\WinNT;D:\Program Files\Microsoft Visual Studio\Common
\MSDev98\Bin;D:\Program Files\Microsoft Visual Studio\Common\Tools;D:\Program Files\
Microsoft Visual Studio\VC98\bin
I have two questions:
Why did this happen? Is there something I did wrong?
Also, how do I add directories to my PATH variable using the console (and programmatically, with a batch file)?

Option 1
After you change PATH with the GUI, close and reopen the console window.
This works because only programs started after the change will see the new PATH.
Option 2
This option only affects your current shell session, not the whole system. Execute this command in the command window you have open:
set PATH=%PATH%;C:\your\path\here\
This command appends C:\your\path\here\ to the current PATH. If your path includes spaces, you do not need to include quote marks.
Breaking it down:
set – A command that changes cmd's environment variables only for the current cmd session; other programs and the system are unaffected.
PATH= – Signifies that PATH is the environment variable to be temporarily changed.
%PATH%;C:\your\path\here\ – The %PATH% part expands to the current value of PATH, and ;C:\your\path\here\ is then concatenated to it. This becomes the new PATH.

WARNING: This solution may be destructive to your PATH, and the stability of your system. As a side effect, it will merge your user and system PATH, and truncate PATH to 1024 characters. The effect of this command is irreversible. Make a backup of PATH first. See the comments for more information.
Don't blindly copy-and-paste this. Use with caution.
You can permanently add a path to PATH with the setx command:
setx /M path "%path%;C:\your\path\here\"
Remove the /M flag if you want to set the user PATH instead of the system PATH.
Notes:
The setx command is only available in Windows 7 and later.
You should run this command from an elevated command prompt.
If you only want to change it for the current session, use set.

This only modifies the registry. An existing process won't use these values. A new process will do so if it is started after this change and doesn't inherit the old environment from its parent.
You didn't specify how you started the console session. The best way to ensure this is to exit the command shell and run it again. It should then inherit the updated PATH environment variable.

You don't need any set or setx command. Simply open the terminal and type:
PATH
This shows the current value of PATH variable. Now you want to add directory to it? Simply type:
PATH %PATH%;C:\xampp\php
If for any reason you want to clear the PATH variable (no paths at all or delete all paths in it), type:
PATH ;
Update
Like Danial Wilson noted in comment below, it sets the path only in the current session. To set the path permanently, use setx but be aware, although that sets the path permanently, but not in the current session, so you have to start a new command line to see the changes. More information is here.
To check if an environmental variable exist or see its value, use the ECHO command:
echo %YOUR_ENV_VARIABLE%

I would use PowerShell instead!
To add a directory to PATH using PowerShell, do the following:
$PATH = [Environment]::GetEnvironmentVariable("PATH")
$xampp_path = "C:\xampp\php"
[Environment]::SetEnvironmentVariable("PATH", "$PATH;$xampp_path")
To set the variable for all users, machine-wide, the last line should be like:
[Environment]::SetEnvironmentVariable("PATH", "$PATH;$xampp_path", "Machine")
In a PowerShell script, you might want to check for the presence of your C:\xampp\php before adding to PATH (in case it has been previously added). You can wrap it in an if conditional.
So putting it all together:
$PATH = [Environment]::GetEnvironmentVariable("PATH", "Machine")
$xampp_path = "C:\xampp\php"
if( $PATH -notlike "*"+$xampp_path+"*" ){
[Environment]::SetEnvironmentVariable("PATH", "$PATH;$xampp_path", "Machine")
}
Better still, one could create a generic function. Just supply the directory you wish to add:
function AddTo-Path{
param(
[string]$Dir
)
if( !(Test-Path $Dir) ){
Write-warning "Supplied directory was not found!"
return
}
$PATH = [Environment]::GetEnvironmentVariable("PATH", "Machine")
if( $PATH -notlike "*"+$Dir+"*" ){
[Environment]::SetEnvironmentVariable("PATH", "$PATH;$Dir", "Machine")
}
}
You could make things better by doing some polishing. For example, using Test-Path to confirm that your directory actually exists.

Safer SETX
Nod to all the comments on the #Nafscript's initial SETX answer.
SETX by default will update your user path.
SETX ... /M will update your system path.
%PATH% contains the system path with the user path appended
Warnings
Backup your PATH - SETX will truncate your junk longer than 1024 characters
Don't call SETX %PATH%;xxx - adds the system path into the user path
Don't call SETX %PATH%;xxx /M - adds the user path into the system path
Excessive batch file use can cause blindness1
The ss64 SETX page has some very good examples. Importantly it points to where the registry keys are for SETX vs SETX /M
User Variables:
HKCU\Environment
System Variables:
HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment
Usage instructions
Append to User PATH
append_user_path.cmd
#ECHO OFF
REM usage: append_user_path "path"
SET Key="HKCU\Environment"
FOR /F "usebackq tokens=2*" %%A IN (`REG QUERY %Key% /v PATH`) DO Set CurrPath=%%B
ECHO %CurrPath% > user_path_bak.txt
SETX PATH "%CurrPath%";%1
Append to System PATH
append_system_path.cmd. Must be run as administrator.
(It's basically the same except with a different Key and the SETX /M modifier.)
#ECHO OFF
REM usage: append_system_path "path"
SET Key="HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment"
FOR /F "usebackq tokens=2*" %%A IN (`REG QUERY %Key% /v PATH`) DO Set CurrPath=%%B
ECHO %CurrPath% > system_path_bak.txt
SETX PATH "%CurrPath%";%1 /M
Alternatives
Finally there's potentially an improved version called SETENV recommended by the ss64 SETX page that splits out setting the user or system environment variables.
Example
Here's a full example that works on Windows 7 to set the PATH environment variable system wide. The example detects if the software has already been added to the PATH before attempting to change the value. There are a number of minor technical differences from the examples given above:
#echo off
set OWNPATH=%~dp0
set PLATFORM=mswin
if defined ProgramFiles(x86) set PLATFORM=win64
if "%PROCESSOR_ARCHITECTURE%"=="AMD64" set PLATFORM=win64
if exist "%OWNPATH%tex\texmf-mswin\bin\context.exe" set PLATFORM=mswin
if exist "%OWNPATH%tex\texmf-win64\bin\context.exe" set PLATFORM=win64
rem Check if the PATH was updated previously
echo %PATH% | findstr "texmf-%PLATFORM%" > nul
rem Only update the PATH if not previously updated
if ERRORLEVEL 1 (
set Key="HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment"
for /F "USEBACKQ tokens=2*" %%A in (`reg query %%Key%% /v PATH`) do (
if not "%%~B" == "" (
rem Preserve the existing PATH
echo %%B > currpath.txt
rem Update the current session
set PATH=%PATH%;%OWNPATH%tex\texmf-%PLATFORM%\bin
rem Persist the PATH environment variable
setx PATH "%%B;%OWNPATH%tex\texmf-%PLATFORM%\bin" /M
)
)
)
1. Not strictly true

Handy if you are already in the directory you want to add to PATH:
set PATH=%PATH%;%CD%
It works with the standard Windows cmd, but not in PowerShell.
For PowerShell, the %CD% equivalent is [System.Environment]::CurrentDirectory.

Aside from all the answers, if you want a nice GUI tool to edit your Windows environment variables you can use Rapid Environment Editor.
Try it! It's safe to use and is awesome!

Command line changes will not be permanent and will be lost when the console closes.
The path works like first comes first served.
You may want to override other already included executables. For instance, if you already have another version on your path and you want to add different version without making a permanent change on path, you should put the directory at the beginning of the command.
To override already included executables;
set PATH=C:\xampp\php;%PATH%;

Use pathed from gtools.
It does things in an intuitive way. For example:
pathed /REMOVE "c:\my\folder"
pathed /APPEND "c:\my\folder"
It shows results without the need to spawn a new cmd!

Regarding point 2, I'm using a simple batch file that is populating PATH or other environment variables for me. Therefore, there isn’t any pollution of environment variables by default. This batch file is accessible from everywhere so I can type:
mybatchfile
Output:
-- Here all environment variables are available
And:
php file.php

Checking the above suggestions on Windows 10 LTSB, and with a glimpse on the "help" outlines (that can be viewed when typing 'command /?' on the cmd), brought me to the conclusion that the PATH command changes the system environment variable Path values only for the current session, but after reboot all the values reset to their default- just as they were prior to using the PATH command.
On the other hand using the SETX command with administrative privileges is way more powerful. It changes those values for good (or at least until the next time this command is used or until next time those values are manually GUI manipulated... ).
The best SETX syntax usage that worked for me:
SETX PATH "%PATH%;C:\path\to\where\the\command\resides"
where any equal sign '=' should be avoided, and don't you worry about spaces! There isn't any need to insert any more quotation marks for a path that contains spaces inside it - the split sign ';' does the job.
The PATH keyword that follows the SETX defines which set of values should be changed among the System Environment Variables possible values, and the %PATH% (the word PATH surrounded by the percent sign) inside the quotation marks, tells the OS to leave the existing PATH values as they are and add the following path (the one that follows the split sign ';') to the existing values.

Use these commands in the Bash shell on Windows to append a new location to the PATH variable
PATH=$PATH:/path/to/mydir
Or prepend this location
PATH=/path/to/mydir:$PATH
In your case, for instance, do
PATH=$PATH:C:\xampp\php
You can echo $PATH to see the PATH variable in the shell.

If you run the command cmd, it will update all system variables for that command window.

In a command prompt you tell Cmd to use Windows Explorer's command line by prefacing it with start.
So start Yourbatchname.
Note you have to register as if its name is batchfile.exe.
Programs and documents can be added to the registry so typing their name without their path in the Start - Run dialog box or shortcut enables Windows to find them.
This is a generic reg file. Copy the lines below to a new Text Document and save it as anyname.reg. Edit it with your programs or documents.
In paths, use \\ to separate folder names in key paths as regedit uses a single \ to separate its key names. All reg files start with REGEDIT4. A semicolon turns a line into a comment. The # symbol means to assign the value to the key rather than a named value.
The file doesn't have to exist. This can be used to set Word.exe to open Winword.exe.
Typing start batchfile will start iexplore.exe.
REGEDIT4
;The bolded name below is the name of the document or program, <filename>.<file extension>
[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\App Paths\Batchfile.exe]
; The # means the path to the file is assigned to the default value for the key.
; The whole path in enclosed in a quotation mark ".
#="\"C:\\Program Files\\Internet Explorer\\iexplore.exe\""
; Optional Parameters. The semicolon means don't process the line. Remove it if you want to put it in the registry
; Informs the shell that the program accepts URLs.
;"useURL"="1"
; Sets the path that a program will use as its' default directory. This is commented out.
;"Path"="C:\\Program Files\\Microsoft Office\\Office\\"
You've already been told about path in another answer. Also see doskey /? for cmd macros (they only work when typing).
You can run startup commands for CMD. From Windows Resource Kit Technical Reference
AutoRun
HKCU\Software\Microsoft\Command Processor
Data type Range Default value
REG_SZ list of commands There is no default value for this entry.
Description
Contains commands which are executed each time you start Cmd.exe.

A better alternative to Control Panel is to use this freeware program from SourceForge called Pathenator.
However, it only works for a system that has .NET 4.0 or greater such as Windows 7, Windows 8, or Windows 10.

As trivial as it may be, I had to restart Windows when faced with this problem.
I am running Windows 7 x64. I did a manual update to the system PATH variable. This worked okay if I ran cmd.exe from the stat menu. But if I type "cmd" in the Windows Explorer address bar, it seems to load the PATH from elsewhere, which doesn't have my manual changes.
(To avoid doubt - yes, I did close and rerun cmd a couple of times before I restarted and it didn't help.)

The below solution worked perfectly.
Try the below command in your Windows terminal.
setx PATH "C:\myfolder;%PATH%"
SUCCESS: Specified value was saved.
You can refer to more on here.

I have installed PHP that time. I extracted php-7***.zip into C:\php</i>
Back up my current PATH environment variable: run cmd, and execute command: path >C:\path-backup.txt
Get my current path value into C:\path.txt file (the same way)
Modify path.txt (sure, my path length is more than 1024 characters, and Windows is running few years)
I have removed duplicates paths in there, like 'C:\Windows; or C:\Windows\System32; or C:\Windows\System32\Wbem; - I've got twice.
Remove uninstalled programs paths as well. Example: C:\Program Files\NonExistSoftware;
This way, my path string length < 1024 :)))
at the end of the path string, add ;C:\php\
Copy path value only into buffer with framed double quotes! Example: "C:\Windows;****;C:\php" No PATH= should be there!!!
Open Windows PowerShell as Administrator (e.g., Win + X).
Run command:
setx path "Here you should insert string from buffer (new path value)"
Rerun your terminal (I use "Far Manager") and check:
php -v

How to open the Environment Variables window from cmd.exe/Run... dialog
SystemPropertiesAdvanced and click "Environment Variables", no UAC
rundll32 sysdm.cpl,EditEnvironmentVariables direct, might trigger UAC
Via Can the environment variables tool in Windows be launched directly? on Server Fault.
How to open the Environment Variables window from Explorer
right-click on "This PC"
Click on "Properties"
On the left panel of the window that pops up, click on "Advanced System Settings"
Click on the "Advanced" tab
Click on "Environment Variables" button at the bottom of the window
You can also search for Variables in the Start menu search.
Reference images how the Environment Variables window looks like:
Windows 10
via
Windows 7
via
Windows XP
via

On Windows 10, I was able to search for set path environment variable and got these instructions:
From the desktop, right-click the very bottom-left corner of the screen to get the Power User Task Menu.
From the Power User Task Menu, click System.
In the Settings window, scroll down to the Related settings section and click the System info link.
In the System window, click the Advanced system settings link in the left navigation panel.
In the System Properties window, click the Advanced tab, then click the Environment Variables button near the bottom of that tab.
In the Environment Variables window (pictured below), highlight the Path variable in the System variables section and click the Edit button. Add or modify the path lines with the paths you want the computer to access. Each different directory is separated with a semicolon, as shown below:
C:\Program Files;C:\Winnt;C:\Winnt\System32
The first time I searched for it, it immediately popped up the System Properties Window. After that, I found the above instructions.

Environment Variable Not recognised

I am setting Environment Variable, Still OS cant recognise. Check this out you will get it.
https://www.dropbox.com/s/raqr4wbtoxxz0b8/1.JPG
I tried with Admin privileges also still same but when I enter
echo %java_home%
or
echo %jre_home%
It is showing path corretly. Why isnt javac command working.
Any Help will be appreciated.

You don't have javac in your path. Setting the JAVA_HOME and/or JRE_HOME environment variables (which aren't needed any more, for the most part) does nothing to the PATH which the command shell uses to find executables.
Put the relevant JDK bin directory in your PATH environment variable instead - and unless you actually need JRE_HOME and JAVA_HOME for some reason, I'd get rid of them. If you do need them, get rid of the "bin" part - it should just be the root JRE directory, e.g.
c:\Program Files\Java\jdk1.7.0_45

Your path JAVA_HOME should be, for example
C:\Program Files\Java\jdk.1.7.0_45
And your Path variable should be
...;%JAVA_HOME%\bin
javac is in the bin folder which should be on your path.

That has nothing to do with Java environment variables.
When you type javac, or any other command, Windows will search the folders in the %PATH% environment variable to find an EXE file with that name.
You need to add your JDK directory to %PATH%.
You also need to restart cmd to pick up the changes.

Include the JRE/JDK path in System variables->PATH as well
After adding path varaibles,restart the cmd

You must restart cmd for new variables to be picked up. And java bin folder needs to be included in path. When you type javac it goes through all folders defined in path to find it.

setting issue of JAVA_HOME and JAVA_PATH

I have been using Eclipse to develop java program on a windows 7 machine. It works. I also typed "java" from the command prompt, it also shows the help message. In other words, I think Java was correctly installed on this machine. However, when I open the "environmental variable" setting on this machine, I cannot find either "JAVA_HOME" setting and "JAVA PATH" setting. What is the problem of this?

Java also copies java.exe and javaw.exe under C:\Windows\System32, there's where your java is running from.
You can confirm that by using where commmand:
On my win7 machine:
>where java.exe
C:\Windows\System32\java.exe

Some environment variables are defined at machine level and some are defined (and overwritten) at user account level. Just do following in windows cmd prompt:
c:\echo %PATH% or just type c:\path
and verify the output.
You can also verify java home path by writing a simple Test class like following:
public class Test {
public static void main(String[]s){
System.out.println(System.getProperty("java.home"));
}
}

There are multitudes of links to be fond on Google regarding how to solve this in Windows. These environment variables typically do not get setup by default when installing java.
Here are some 10 second finds with with answers:
How to set java_home on Windows 7?
Setting the JAVA_HOME Variable in Windows
Installing Java on Windows 7 and setting-up the JAVA_HOME

Check you PATH variable in Environment Variables. It must be set to jreInstallation/bin. Windows does not pick up java command from JAVA PATH, it picks java command from PATH variable.
Also note that once you install JDK, path is not set by installation to jdkInstallation/bin, you need to set it up explicitly.So unless you set the path to jdkInstallation/bin, javac wont be recognized.

Check your path variable in windows environmental variables. At least Java path should be there .
It may looks like this.
%SystemRoot%\system32;%SystemRoot%;%SystemRoot%\System32\Wbem;%SYSTEMROOT%\System32\WindowsPowerShell\v1.0\;C:\Program Files (x86)\Java\jdk1.7.0\bin

You should set path and classpath variables.
Here's the link you can follow for step by step instructions.
[http://abodeqa.wordpress.com/2012/08/11/how-to-set-path/][1]

With Java, Groovy, Git, Heroku, Maven, and many other projects, what I always do is this:
1. Unzip the software package into a directory, for example:
C:\AeroFS\Java\jdk1.7.0_25
C:\AeroFS\Groovy\groovy-2.0.5
2. Create a HOME variable, such as JAVA_HOME or GROOVY_HOME that points to the
above locations.
3. Put these in your default system path by editing your PATH variable and
adding %JAVA_HOME%\bin and %GROOVY_HOME%\bin to the end of your PATH. In
the case of JAVA_HOME only, you might want to put it at the beginning of
the PATH to override the java.exe that rests in the WINDOWS directory
location.

Change where Java looks for javac.exe

I am trying to upload my GAE app using the console in windows. I am getting the error:
cannot find javac executable based on java.home tried, "C:\Program Files\Java\jre6\bin\javac.exe" and "C:\Program Files\Java\bi
n\javac.exe"
Unable to upload app: cannot find javac executable based on java.home, tried "C:
\Program Files\Java\jre6\bin\javac.exe" and "C:\Program Files\Java\bin\javac.exe
javac.exe is located in C:\Program Files\Java\jdk1.6.0_18\bin how do I tell java thats where it is

You must set the JAVA_HOME environment variable to refer to the top-level folder where java is installed. Right-click "My Computer", Properties, Advanced, Environment Variables. If there's an existing JAVA_HOME variable, then correct it so that its value is
C:\Program Files\Java\jdk1.6.0_18
If there is no existing variable, then create one by using the "New" button. It's up to you whether to do it for the current user or for the system.

Do you have two java versions installed?
From the information the sun jre and the Open jdk? The jre has no javac.exe and therefore cant find it.
Try to start your jar with C:\Program Files\Java\jdk1.6.0_18\bin\java.exe instead of only java, if that doesn't help add the -Djava.home="C:\Program Files\Java\jdk1.6.0_18" option to the call.

The error message makes it clear that the lookup is based on java.home, have you tried adjusting that?
This output looks like it is coming from some sort of script which may have it's own definition of java.home which you need to change.

The easiest solution for this problem which I found is to use the JAVA_HOME variable in the script file.
This is the content of my bin\appcfg.cmd:
#"%JAVA_HOME%"\bin\java -cp "%~dp0\..\lib\appengine-tools-api.jar" com.google.appengine.tools.admin.AppCfg %*
Note: you should also check if JAVA_HOME points to an existing JDK

The other way you can do set classpath variable using set CLASSPATH=C:\Program Files\Java\jre6\bin\javac.exe\jdk1.6.0_18 in command prompt, but it works for single session.Everytime you need to set the variable.

Set your JAVA_HOME environment variable to C:\Program Files\Java\jdk1.6.0_18. Note that this variable points to the JDK location, not (unlike the PATH environment variable) to the path where the executables reside.

How can I set the PATH variable for javac so I can manually compile my .java works?

Here's the address on my drive:
C:\Program Files\Java\jdk1.6.0_18\bin
How would I go about setting the path variable so I can go in command window (windowskey+r "cmd") and be able to type things like:
javac TestApp.java
I'm using Windows 7 Professional.

That would be:
set "PATH=%PATH%;C:\Program Files\Java\jdk1.6.0_18\bin"
You can also append ;C:\Program Files\Java\jdk1.6.0_18\bin to the PATH in the user environment dialog. That would allow you to use javac and other java tools directly form any cmd shell without setting the path first. The user environment dialog used to be somewhere in the system properties in XP, I have no idea where it is in Windows 7.

Typing the SET PATH command into the command shell every time you fire it up could get old for you pretty fast. Three alternatives:
Run javac from a batch (.CMD) file. Then you can just put the SET PATH into that file before your javac execution. Or you could do without the SET PATH if you simply code the explicit path to javac.exe
Set your enhanced, improved PATH in the "environment variables" configuration of your system.
In the long run you'll want to automate your Java compiling with Ant. But that will require yet another extension to PATH first, which brings us back to (1) and (2).

Step 1: Set the PATH variable JAVA_HOME to the path of the JDK present on the system.
Step 2: in the Path variable add the path of the C:\Program Files\Java\jdk(version)\bin
This should solve the problem.
Happy coding!!

Type cmd in program start
Copy and Paste following on dos prompt
set PATH="%PATH%;C:\Program Files\Java\jdk1.6.0_18\bin"

Follow the steps given here
http://www.javaandme.com/
after setting variable, just navigate to your java file directory in your cmd and type
javac "xyx.java"
or if you don't navigate to the directory, then simply specify the full path of java file
javac "/xyz.java"

First thing I wann ans to this imp question: "Why we require PATH To be set?"
Answer : You need to set PATH to compile Java source code, create JAVA CLASS FILES and allow Operating System to load classes at runtime.
Now you will understand why after setting "javac" you can manually compile by just saying
"Class_name.java"
Modify the PATH of Windows Environmental Variable by appending the location till bin directory where all exe file(for eg. java,javac) are present.
Example : ;C:\Program Files\Java\jre7\bin.

only this will work:
path=%set path%;C:\Program Files\Java\jdk1.7.0_04\bin

You don't need to do any complex command-line stuff or edit any system code.
You simply have to open Computer, showing all of your disks and open properties.
From there, go to Advanced System Settings and click Environment Variables.
Scroll down in the lower list box and edit Path.
Do not erase anything already there. Put a ; after it and then type in your path. To test, open command prompt and do "javac", it should list around 20 programs.
You would be finished at that point.
By the way, the command to compile is javac -g not just javac.
Happy coding!

Trying this out on Windows 10, none of the command-line instructions worked.
Right clicking on "Computer" then open Properties etc. as the post by Galen Nare above already explains, leads you to a window where you need to click on "new" and then paste the path (as said: without deleting anything else). Afterwards you can check by typing java -version in the command-line window, which should display your current java version, if everything worked out right.