Setting Environment variable GPDIR, Fixing the PATH

For GEMPACK to run easily, you must make sure that the GEMPACK directory (usually C:\GP) is on your PATH, and that the Environment variable GPDIR is set to the GEMPACK directory.

If you allowed the GEMPACK installer or BuildGP to make changes to your PATH and the Environment variable GPDIR (see here), this may have already been done.

If you did not allow the installer or BuildGP to make changes to your PATH and GPDIR, you must make the required changes yourself.

PATH and GPDIR for Windows XP or later

The usual method to change the PATH and set the Environment variable GPDIR is by editing the System Properties - see steps 1 to 4 below.

The important changes are:

If you allowed the installer to make these changes, you can check that this has been done correctly using the steps 1 to 4 below. If you did not allow the installer to make these changes, carry out the following steps 1 to 4.

  1. Right click on "My Computer".
    Select Properties | Advanced | Environment Variables
  2. Select the PATH variable and add the GEMPACK directory to it (separated by a semicolon ;). You can add the GEMPACK directory to the beginning or end of the current PATH as you prefer. [If you have a previous GEMPACK directory on your Path, replace it with the new GEMPACK directory.] Click on the Set button to accept this change. If you are using Source code GEMPACK, check that the directory containing the Fortran compiler is also on the PATH. If not, add this directory.
  3. Set a new Environment variable named GPDIR and give it a value C:\GP10 (or whatever your GEMPACK directory is called.) Select the Set button to accept this change.
    Note that if you have installed GEMPACK in the default directory C:\GP, it is not necessary to set the Environment variable GPDIR. The GEMPACK programs will assume that C:\GP is the GEMPACK directory, which contains your GEMPACK licence and the GEMPACK libraries and programs, if GPDIR is not set.
  4. If you are using Source code GEMPACK you may also need to set the TMP environment variable as well.
  5. Click on the Ok button to accept these changes to the Environment.

These changes will take effect when you next start Windows programs or open a new DOS box. Test these changes by opening a new DOS box and entering "SET". This should show the altered path and the new Environment variable GPDIR.

If you are running Windows 7 or Vista, see these detailed instructions for editing the PATH and other environment variables.

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