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"Javac" doesn't work correctly on Windows 10

the problem is that I upgraded to Windows 10 and now I'm installing my tools to programming and now that I installed the JDK 7 of Java, when I try to use in the cmd the command:
- "javac"
The result of this is: "javac" is not recognized as an internal or external command...
But I was edited the PATH with the correct link of jdk, because when I use "java", it is ok.
Now, I tried in the console with this command: PATH=%PATH%;"C:\Program Files\Java\jdk1.7.0_79\bin"
And when I executed the command "javac" it works, but now, when I open other console, it doesn't work, or when I restart the console, this command is not recognized.
What could be the problem?

java is part of the JRE, not the JDK.
You need to add the JDK bin to the system PATH, in
"Control Panel" | System | Advanced | "Environment Variables"

Her's how I configure System variable on Windows 10 :

I am totally new to java and spent hours trying to get the problems with PATH and CLASSPATH worked out. There was one person who said to restart the command prompt after you modify the environment variables; that was it for me. While you are testing different configurations, make sure to relaunch the command prompt before testing. It seems like there are at least 2 different ways of setting this up. I went with the following:
1) In System Variables, add
JAVA_HOME = c:\program files (x86)\java\jdk1.8.0_121
2) In System Variables, add the following to existing Path...
%JAVA_HOME%\bin
That's it.
No need for quotes around anything. No double forward slashes or anything else. I think it would also work if I removed the java_home variable and just listed the explicit path to bin in the PATH variable, but I'm not touching it again now that it finally works.

After adding C:\Program Files\Java\jdk1.8.0_73\bin to the system variables I turned off my command prompt and opened another one. Then it worked.

Maybe a bit late, but i had same problem.
Click on "Move up" button for Java path and move it at top.
It fixed problem for me

just add C:\Program Files\Java\jdk1.7.0_80\bin as the path in environmental variables. no need to add java.exe and javac.exe to that path. IT WORKS

I added below Path in environment variable
;%JAVA_HOME%/bin instead of %JAVA_HOME%\bin
in my case , it fix the problem

I had the same issue on Windows 10 - the java -version command was working but javac -version was not. There are three things I did:
(1) I downloaded the latest jdk (not the jre) and installed it. Then, I added the jdk/bin path tan o environment variable. In my case, it was C:\Program Files\Java\jdk-10\bin. I did not need to add the ; for Windows 10.
(2) Move this path to the top of all the other paths.
(3) Delete any other Java paths that might exist.
Test the java -version and javac -version commands again. Voila!

For some reason it worked for me to add quotation marks to the path folder on windows 10. not C:\Program Files\Java\jdk 1.8.0_111\bin, but "C:\Program Files\Java\jdk 1.8.0_111\bin".

now i got it finally! make sure that there are no spaces before and after the path and put the semi-colon on both sides without spaces

The PATH is for current user, instead you can add a CLASSPATH and below link would help you more PATH and CLASSPATH

I added below Path in environment variable
C:\Program Files\Java\jdk1.8.0_91\bin
and then compiled the program but got the error then I restarted the system and again compiled the program
This time it worked :)

Add java path to environment variables and move it to the top of all the paths available there. It worked for me.

To be sure about your path, you can use double quotes " to locate the path or if you are in Windows, you can browse to path to select "C:\Program Files\Java\jdk1.8.0_121\bin" folder.

in the search window type 'environment variables' this should give you a link to editing the variables. On the variables editing page there is an upper section and a lower section in the lower section add NEW,type path C:\Program Files\Java\jdk-10\bin this worked great for me and it finds the compiler all the time.

Kind of beating a dead horse now but, I want to clarify one thing that may not be quite so obvious. Yes indeed you need to edit the PATH environment variable as already stated many times. The key for me was to edit the PATH under SYSTEM variables. I had inadvertently edited the PATH under USER variables. Why did this matter? On my machine I have to log in as an Administrator to edit environment variables. So editing the User variables was not helping because I run the command prompt under my login (non-admin) account. Grrr!
Also, I found that closing the command prompt window, and re-opening it after the PATH variable update was required. Changing the order of the values, adding semi-colons, etc. didn't make a difference for me.
Cheers

If you have set all PATH variables correctly after installation, just restart it.
I had the same problem, I had also installed new Windows7 OS then I upgraded it to Win 10. Then i started setup necessary tools like IntelliJ, Java jdk,jre, eclipse so on.
In cmd, java -version worked but javac compiler got unrecognized. I checked and all good, the files in the folders, path are correct and so on.
I restarted and checked it again in cmd ,it worked.

what I did is:
I typed ; accidentally in front in the path variable and then hit OK, after this if I again edit it was nowhere going to the same page as earlier, it opened a new page as defined for user variables and then I was able to remove double quotes in front of the PATH VARIABLE.
Everything worked fine then. :)
Did it just now.

Add
PATH = C:\Program Files\Java\jdk1.8.0_66\bin
in Advanced system setting. Then Choose Environment Variable.

for windows 10 Users Use Java path( JDK Bin location) AS "C:\Program Files\Java\jdk-9.0.1\bin" it will work.

Points to remember, do as the image shows. Move the highlighted bar up using move up button, this will help.

Compiling and running java application using powershell

I am trying to compile and a sample Helloworld.java file.
I have my jdk installed in C:\Program Files\jdk1.7\bin.
And I have my Helloworld.java in C:\Helloworld.java
I am actually a novice in both powershell and java.
I got some examples from web regarding this but many of them advice to run it like this:
java.exe -classpath $Env:CLASSPATH C:\Helloworld.java
But when I give this in powershell I get an error called 'CLASSPATH' is not defined even after adding it in env variables.
And when I try to compile the code with the following syntax:
$javac C:\Helloworld.java I get an error "javac is not recognised as a token".
So, I am literally lost in this topic . Any step by step procedure to run java programs using powershell for dummies like me will be greatly appreciated.

Setup environment variables in your system.
set JAVA_HOME to C:\Program Files\jdk1.7
add to PATH variable the string %JAVA_HOME%\bin
open new cmd session.
navigate your java source folder.
use javac to compile your java files.
UPDATE:
also if you are experiencing difficulities upon launching an executable via PowerShell check this Microsoft TechNet article

The variables you speak of do not exist in PowerShell as you name them.
The correct variable names are
$Env:JAVA_HOME: C:\jdk1.6.0;
$Env:PATH: C:\jdk1.6.0\bin;.;
$Env:CLASSPATH: C:\jdk1.6.0\lib;.;
As they all must be defined in the ENV: PSDrive

To answer it in a much simpler way , its the path problem .
You probably not have set env variables that's it.
This is how you should set it:
JAVA_HOME: C:\jdk1.6.0;
PATH: C:\jdk1.6.0\bin;.;
CLASSPATH: C:\jdk1.6.0\lib;.;
And later if you open a cmd prompt and type java -version , if you are able to see the java installed version then you are good to go.

Trouble in Setting Java Environment Path on Ubuntu (libjvm.so: cannot open shared object file: No such file or directory)

Found the solution!
Ubuntu by default ignore the command "RD_LIBRARY_PATH" therefore I need to add those codes in ".bashrc" instead of "/etc/environment" or .profile.
it now work perfectly fine!
I am trying to run a program that reads Java method from C/C++ code. (I made it on Windows successfully, now, I am working on Linux)
I made it successfully compiled and run on Ubuntu, however, the problem is..
Whenever I try to run the program, I have to type following commands on terminal..
source /etc/environment
./invoke #program name is invoke
If I do not type "source /etc/environment" every time I boot my PC, the error message I get is...
error while loading shared libraries: libjvm.so: cannot open shared object file: No such file or directory
Ok. Here is what I added in /etc/environment
export PATH="$PATH:/usr/lib/jvm/jdk1.7.0_25_x64/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games"
export JAVA_HOME=/usr/lib/jvm/jdk1.7.0_25_x64
export LD_LIBRARY_PATH=$JAVA_HOME/jre/lib/amd64:$JAVA_HOME/jre/lib/amd64/server
What I want is that, as you know, I want to run the program without typing "source /etc/environment".
I also tried typing those PATHs on /etc/profile, but result was same... I should type "source /etc/profile" every time I reboot my PC..
How to make it permanently applied to whole range of System without typing "source /etc/environment" stuffs everytime I boot?
if you need to see source code of the program, here is downloadable address:
http://cfile237.uf.daum.net/attach/247819495212DF1C07B9EB

This worked for me:
For x86:
export LD_LIBRARY_PATH=/usr/lib/jvm/default-java/jre/lib/i386:/usr/lib/jvm/default-java/jre/lib/i386/server
For x86_64
export LD_LIBRARY_PATH=/usr/lib/jvm/default-java/jre/lib/amd64:/usr/lib/jvm/default-java/jre/lib/amd64/server

I had the same problem of setting the path(permanently) however I was using Red Hat, If you look change PATH permanently on Ubuntu it might help you. There was a file on Red Hat .profile that once you add your exports statements, they will get loaded when the computer starts. :) There should be the kind of file for ubuntu
export PATH="$PATH:/usr/lib/jvm/jdk1.7.0_25_x64/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games"
export JAVA_HOME=/usr/lib/jvm/jdk1.7.0_25_x64

Put "-Djava.library.path=FULL_PATH_HERE/jre/lib/amd64" as a JVM option in your C code.
Edit the full_path_here part.
The path is allowed to be relative, but I don't think you can use $JAVA_HOME as a placeholder for the environment variable.

Found the solution!
Ubuntu by default ignore the command "RD_LIBRARY_PATH" therefore I need to add those codes in ".bashrc" instead of "/etc/environment" or .profile.
it now work perfectly fine!

add the path of the missing libraries in the file /etc/ld.so.conf
execute the following command: ldconfig
this way, you'll add the new libraries to the default ones.
To check whether the new libraries have been linked,
execute the following command: ldconfig -p
to have the list of libraries currently linked by default.

setting up classpath. javac is not recognized

I am trying to run my java program from command line.
I read an article about setting up classpath, but I get an error of javac is
not recognized as internal or external command. What should I do? (I dont want to set a permanent CLASSPATH)
This is what I have done in my command line
D:\user> set path=%path%;C:\Program Files\Java\1.7.0_07\bin
D:\user> cd testing
D:\user\testing> javac firstProgram.java
'javac' is not recognized as an internal or external command,
operable program or batch file.
Thank you

Assuming that the PATH is correct1, the most likely cause is that you have a JRE installation ... and a JRE doesn't include a java compiler. You need a JDK installation if you want to compile from the command line.
(You can confirm this by looking in the C:\Program Files\Java\1.7.0_07\bin directory to see if it contains a javac.exe file. A JRE won't ...)
Where can I find the Java compiler to download..
You need to download one of the JDK installers; see http://www.oracle.com/technetwork/java/javase/downloads/index.html
1 - I don't think quotes are required in a PATH variable on Windows. At least that's what various examples that Google found for me seem to imply. But I've never really understood the logic behind quoting in Windows ...

Its an issue related to Program Files.
First make sure that your JDK Folder is installed in Program Files or Program Files(x86) or any other folder.
Then you should use the path of bin folder in " ". Because command prompt does break the string at space. When you will write it in " " then it will take is as a whole String.
You try these commands
set path=%path%;"C:\Program Files\Java\1.7.0_07\bin"
or
set path=%path%;"C:\Program Files(x86)\Java\1.7.0_07\bin"
It might help you to get out of this.

Better do it in Environmental variable and check it!

try below command is recognized from command prompt
C:\Program Files\Java\1.7.0_07\bin\javac ab.java
This is just to verify your javac

Here's how you can set the path temporary, meaning if you close and reopen "command prompt" you will have to set the path again.
Assuming the path is C:\Program Files\Java\jdk1.6.0\bin
TYPE IN C:\Program Files\Java\jdk1.6.0\bin AND HIT ENTER
that's it.

The commands D:\user> set path=%path%;C:\Program Files\Java\1.7.0_07\bin works well for me

Adding few more information to this:
Please check the version of JDK and JRE installed on your computer. Recently I faced the same problem even after setting the PATH. It gives the error "javac - command is not recognised"
Solution is there must be similar versions of JDK as well as JRE
E.g.: JDK 1.7.75 along with JRE 1.7.75

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.