Installation Notes for Windows


  1. Run windows_x86_32.exe (Windows 32bit) or windows_x64_64.exe (Windows 64bit): Both files are available from The 32 bit version works both on a 32bit and on a 64bit operating system. Please note that the installation may require administrative privileges on your machine.

    You have two options to run the installer: In default or advanced mode. In the default mode, the installer will prompt you for the name of the directory in which to install GAMS. We call this directory the GAMS directory. You may accept the default choice or pick another directory. Please remember: if you want to install two different versions of GAMS, they must be in separate directories.

    If you choose to use the advanced mode, the installer will also ask you for a name of a start menu folder, if GAMS should be installed for all users, if the GAMS directory should be added to the PATH environment variable and if a desktop icon should be created.

    For automating the installation of GAMS, it is possible to provide the command line parameters /SP- /SILENT. This will install GAMS in a non-interactive manner using default settings. Note that depending on the security settings, the User Account Control asking for permission might still be active.

    Under Windows 10 the Windows Installer package may not update system environment variables (see Microsft Support). To work around this issue, log off of Windows after the installation, and then log on again.
  2. Copy the GAMS license file: You will be asked for the GAMS license file (gamslice.txt) during the installation. The license file is nowadays sent via email, with instructions. You can also request a demo license from If you don't have a license file yet, choose No license when asked for the GAMS license options. You can install a license later by either manually create the license file gamslice.txt in the GAMS system directory or use the corresponding GAMS Studio dialog.

    If you have a license file you wish to copy to the GAMS directory at this time, answer Copy license file. You will now be given the opportunity to browse the file system and find the license file gamslice.txt. When you have found the correct file, choose open to perform the copy. Instead of copying a license file you could also copy the content of that file to the clipboard. If you have done this, select Copy license text from clipboard.

  3. Choose the default solvers: Run the GAMS IDE by double clicking gamside.exe from the GAMS directory. To view or edit the default solvers, choose FileOptionsSolvers from the IDE. You can accept the existing defaults if you wish, but most users want to select new default solvers for each model type.
  4. Run a few models to test the GAMS system: The on-line help for the IDE (HelpGAMS IDE Help TopicsGuided Tour) describes how to copy a model from the GAMS model library, run it, and view the solution. To test your installation, run the following models from the GAMS model library:
    LP:    trnsport (objective value:  153.675)
    NLP:   chenery  (objective value:  1058.9)
    MIP:   bid      (optimal solution: 15210109.512)
    MINLP: procsel  (optimal solution: 1.9231)
    MCP:   scarfmcp (no objective function)
    MPSGE: scarfmge (no objective function)

Visual C++ Redistributable Dependency

  • Some solvers in the system as well as GAMS Studio have dependencies on certain Visual C++ libraries. These are present on most Windows systems but are missing on some. If you get a complaint about missing libraries on startup of GAMS Studio or when solving a model, please run the appropriate installer for these libraries, which can be found in the GAMS installation folder:
    • 32-bit GAMS version: run vcredist_x86.exe, found in [GAMS system]\apifiles\C++\lib\vs2013, followed by vcredist_x86.exe, found in [GAMS system]\apifiles\C++\lib\vs2015
    • 64-bit GAMS version: run vcredist_x64.exe, found in [GAMS system]\apifiles\C++\lib\vs2017

Command Line Use of GAMS

Users wishing to use GAMS from the command line (aka the console mode) may want to perform the following steps. These steps are not necessary to run GAMS via the IDE.

  1. We recommend to add the GAMS directory to your environment path in order to avoid having to type in an absolute path name each time you run GAMS. Run the installer in advanced mode and mark the check-box Add GAMS directory to PATH environment variable.
  2. Run the program gamsinst: gamsinst is a command line program used to configure GAMS. It prompts the user for default solvers to be used for each model type. If possible, choose solvers you have licensed, since unlicensed solvers will only run in demonstration mode. The solver defaults can be changed by:

    a. rerunning gamsinst and resetting the default values

    b. setting a command line default, e.g. gams trnsport lp=bdmlp

    c. by an option statement in the GAMS model, e.g: option lp=bdmlp;

    The system wide solver defaults are shared by the command line and the GAMS IDE, so you can also choose to set these defaults using the GAMS IDE.