If you are looking for an "offline" fix because a game says a .dll is missing, you should download the . It installs all legacy components that modern Windows might skip. To help you get the right files, let me know: Are you getting a specific error message ? Which game or app won't start?
While named a "web installer," running this executable allows you to download all necessary DirectX 9, 10, 11, and 12 files to a folder of your choosing, making it a portable offline package. directx 12 windows 10 64 bit offline installer link