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.