Can't find $ROOTSYS directory

I’ve been reading the root user guide and it mentions the directory $ROOTSYS many times but I can’t find it. Though I think it means the root folder we use as it mentions $ROOTSYS /bin , and $ROOTSYS /tutorials and all, but I don’t get anything when I type $ROOTSYS in command line.

Also I can’t find $ROOTSYS/test as given in the text. I also tried repeating the command echo $ROOTSYS in command prompt but it just gives $ROOTSYS, unlike what is said in the text.

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ROOT Version: 6.18/04
Platform: Windows 10
Compiler: Not Provided


How did you install ROOT? Downloading binaries from ROOT web-page? $ROOTSYS is usually a directory that points to your local installation of ROOT. You can try to source script that should be located in your root installation directory and then try to print $ROOTSYS again.

Yes I did install the binary and directly put the folder somewhere I can easily use. I think there are some instructions about making changes to a file that integrates root to your command line in Linux, but I did not find any such equivalent for Windows.

Could you guide me how to do it?

@bellenot, I don’t have an example of ROOT installation on Windows. Perhaps you can help here?

Thank you!


To set ROOTSYS on Windows, you can either:

  • From the command prompt, execute thisroot.bat, which is located in the bin directory of the ROOT installation directory
  • Set ROOTSYS in the system’s environment variables and add %ROOTSYS%\bin in your PATH environment variable.

As you can see, on Windows, the environment variables are accessible enclosed in two % characters: %ROOTSYS% instead of $ROOTSYS (on Linux)

Cheers, Bertrand.

What exactly do you mean by being accessible?

access (query) the environment variable with:

echo %ROOTSYS%

instead of: