I downloaded fallout 4 on steam and when I go to launch it I get this message: "The application was unable to start correctly (0xc000007b)" .

Anybody Know how to fix this????

same thing here, i tried everything from net framework reinstall to visual c++, running in admin mode etc etc

EDIT: after hours of trying i ran "dependency walker" and loaded the game exe in it and selected profile to check what is loading and found the culprit: x3daudio1_7.dll
i had the same problem with other games before and i didnt check it now
just download that file again from google, put it in system32 folder and syswow64 in your windows folder and restart your pc and its working

Thanks for the help. I tried this and it still didn't work. I'm now getting an error message saying "x3daudio1_7.dll missing" which is weird because I followed the steps you laid out. I downloaded directx end-user runtime web installer aswell to see if that would work, it didn't, then I upgraded to windows 10. that didn't work either. lol. Also when I shoved the x3daudio1_7.dll file into syswow64 it gave me the option to copy and replace, which must mean it's already there? So I copied and replaced, should I have done this?

i've had the same file in both my folders because ive had the "x3daudio1_7.dll missing" error in some other games a while ago but it seems it got bugged somehow...hmmm..try opening your command prompt (just type in "command" in your search box in start menu and its the first option on the top)
then type in "regsvr32 /u X3DAudio1_7.dll", hit enter, then type in "regsvr32 /i X3DAudio1_7.dll" then hit enter again

if the game doesn't start after that and displays the same "missing" error then you downloaded the wrong version (32bit)

if that is the case then go to dll-files.com and find that file and it will offer you 32 and 64 bit versions and download that 64 one and replace it.