i copied all the files to the FS9 sounds folder... and replaced the 777-300's sound.dll file with the one in the pack. i have been installing and uninstalling other 3rd party aircraft today too.. but i havent messed with the sounds
I just checked the FS9 "Sound" folder and there's no "SOUND.DLL" file in it. Also the default 777-300 sound is aliased to the 777-400. FSSound.dll is a third party add on file but "SOUND.DLL" is a file in FS9 "Modules" folder. If you overwrote or moved that then you won't have any sounds in the sim. Check in the "Modules" folder for "SOUND.DLL". If that isn' t there or isn't the Microsoft version then that's likely your problem. You said you put a "SOUND.DLL" into the 777-300 folder. Check there first. Maybe moving it back into the "Modules" folder will do the trick.