OK, so I can't run Java executable files of any sort on my Windows 7 PC. The one in particular I'm trying to use is the Forge installer for Minecraft. Normally, an installer window should open when I double click the file. I have Java installed and I set it to open with Java (TM) SE Binary but all that does is make the command prompt window open and then close again instantly. I have tried using the command method to open it but then it comes up with the error saying Error:

Unable to access jarfile runable_jar.jar

I have downloaded the JDK file because I heard that was something I needed, but I'm not sure where to put it so it will do what it is supposed to.

Was there something else I needed to download or is there something wrong with the version of Java I'm using (I checked and it's at the latest update). By the way I have a Windows 7 64 bit if that helps.

  • I have no idea how to solve your problem, but I just wanted to say this: To run Java files, you only need the JRE (Java Runtime Environment). Although the JDK (Java Development Kit) includes the JRE, it is actually meant for developing Java apps and therefore contains all sorts of things you likely won't ever need. Unless you intend to develop in Java, the JDK is mostly a waste of space. By the way, have you tried the Installer-win? It's an .exe, so it should work even without JDK/JRE.
    – Nolonar
    Aug 1, 2015 at 21:41
  • To clarify: You are using java -jar runable_jar.jar, rather than just java runable_jar.jar? The latter produces an error that might be the same you get, but I'm not sure since it's in German for me.
    – MrLemon
    Aug 1, 2015 at 22:30
  • I have no idea what the exact command you are using so I can't say what in the command line might be an issue. In Windows if you have JRE installed you should be able to right click and say OpenWith JRE.
    – ydobonebi
    Aug 1, 2015 at 22:47
  • Make sure you haven't set another program as the default opener for .jar files.
    – 2xedo
    Aug 2, 2015 at 2:12
  • maybe i don't have the JRE, i thought it might come with the SE binary, can some give me a download link for this?
    – Max Browne
    Aug 2, 2015 at 17:38

1 Answer 1


OK, here are some things to check:

Make sure to run the command java -jar [filename].jar Replace [filename] with whatever the name of the jar file you want to open is. You have to be careful that you add the .jar at the end, or it will produce the error you said.

On the Forge download page, did you download the Latest version or the Recommended version? If you installed the latest, you might want to give the recommended version a shot.

Another thing on the side is that the JDK (Java Development Kit) should not be needed here, just the JRE (Java Runtime Environment). Make sure you have that.

  • wow thanks man it works :D i think i was just using the wrong command at first.
    – Max Browne
    Aug 2, 2015 at 17:43
  • 1
    @MaxBrowne Glad I could help :)
    – APCoding
    Aug 3, 2015 at 0:20

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