You cannot download Feature Level 11.1 as a standalone file. It is a capability of your graphics card. To enable it:
Once you have updated Windows and your drivers, you can verify if 11.1 is active. d3d feature level 11.1 download
If 11_1 is missing from that list, your system cannot run software that strictly requires Direct3D Feature Level 11.1. How to "Download" and Install D3D Feature Level 11.1 You cannot download Feature Level 11
to right-click your card under "Display adapters" and select "Update driver". 3. Install Windows Platform Updates (Windows 7/8) d3d feature level 11.1 download