xinput1_4.dll
This file is not a system component: windows itself, not a download. Restore it from the source that installed it rather than downloading a replacement.
The error names your specific file, but the fix is the same for the whole family: the whole DirectX family and the one runtime that installs all of it.
If the file is already there and Windows still complains, read the message again: “entry point not found” is a different problem from a missing file, and installing the runtime again will not solve it.
And if the box says RUNDLL rather than naming a program, the fix runs the other way: something left an instruction behind pointing at a file that is meant to be gone, so restoring the file is the wrong move.
Do not download this DLL on its own
Searching for a missing DLL by name leads to sites that hand you that single file. It is one of the oldest and most effective malware delivery methods there is, and a system DLL from an unknown source is indistinguishable from a deliberately modified one. There is never a legitimate reason to obtain a runtime component that way.
The same goes for the tools that offer to do it for you: what a DLL repair tool can and cannot actually fix.
What it is
The current XInput controller library, which is part of Windows rather than a redistributable. Unlike xinput1_3.dll, it is not included in the DirectX End-User Runtime.
Where you see it: Games with gamepad support, usually on a Windows installation with damaged system files.
Because Windows supplies this one, a genuine absence means system corruption: run "sfc /scannow" followed by "DISM /Online /Cleanup-Image /RestoreHealth". If a game asks for xinput1_3.dll instead, that is the legacy version and the DirectX End-User Runtime does provide it.
Why there is nothing to download here
There is no verified download we can offer for this one, because installing a file is not the fix. The steps above are what actually resolves it. That distinction matters: the sites ranking for this file name are selling a download that would not have helped even if it were safe.