This file is not available on the nexus! Yukichigai Unofficial Patch (YUP) The NVSE files must be dropped into the main directory where your exe file is located. You have to simply open the file and your game directory and drag and drop everything except for the SRC folder and the read me files.
Installing New Vegas Script Extender should be done manually. A lot of mods on the nexus require the script extender including some of the mods on this list. New vegas script extender is another absolutely essential mod that is required by most other mods. This is however a NVSE plugin so you must have the script extender installed. It will get rid of many of the crashes you will experience throughout the game. Even if one is doing a vanilla playthrough they should still get this mod. New vegas Anti Crash is a mod that is absolutely essential no matter what. Be aware that your game can crash if mods are installed incorrectly, nexus mod manager or even better, mod organizer is highly recommended! New Vegas Anti Crash (NVAC)
This guide assumes you have basic computer literacy and know how to at the very least find your New Vegas folder. A guide to show all performance and stability boosting mods that are essential to making Fallout New Vegas a more stable game and tools and mod managers to help with modifying your game.