Specific PC, Windows 7 won't run Flash EXE

I’m trying to avoid using AIR or running the SWF through the standalone Flash Player, but Windows 7 on a few specific PCs won’t run the Flash .EXE projector - any ideas? The projector does load files (jpg/xml) from an assets folder, but the Document Class constructor isn’t even executing. This only happens on a few specific computers. Does anyone know if it could be a Windows 7 security setting?

Thanks in advanced.