A legitimate, unpatched vanilla halo.exe file is typically between 2 MB and 5 MB. If a download for just the executable is dozens of megabytes or an .exe wrapped inside an installer ( .msi or .bat ), avoid it.
Before running halo.exe :
-window : Forces the game to launch in windowed mode, preventing fullscreen resolution mismatch crashes. haloexe file download work
Which are you trying to play? (e.g., Original 2003 PC, Custom Edition, or Master Chief Collection) A legitimate, unpatched vanilla halo