When users launch GIFTS or IGAM or any module of GIFTS, they most often use a shortcut that points to a server location where the GIFTS.exe or gfwGAM.exe is located. If that .exe file is missing, then the program simply will not launch. As for why the .exe files are missing, there is a good chance that someone tried to uninstall GIFTS.
If you are being told that you cannot launch GIFTS/IGAM/etc because the .exe file is missing, the best course of action is to ask your IT team if they can restore the executables from when they last took a snapshot of your GIFTS directory. Without the .exe files, the program will not launch.
Often, these go missing because someone chooses to uninstall GIFTS. When uninstalling, the program begins to remove .exe files from the GIFTS directory. We do not recommend uninstalling for any purpose - if GIFTS is acting oddly, we recommend a reinstall instead as this acts as a repair.