The New Vegas Script Extender is a special scripting tool developed for use with "Fallout" games. In order to modify or create events in the "Fallout" world, you will need a functional copy of the NVSE software. While this software works with Steam-based "Fallout" installs, it can also operate as a standalone script editor if you have installed "Fallout" from a disc or digital download. Once installation is complete, it will run the same regardless of your "Fallout" purchase method.
Download the most recent version of "NVSE" from Silverlock.org. Save the file to your desktop for easy access.
Unzip the file and place the new folder on your desktop.
Pres the Windows key and E simultaneously to open the Windows Explorer. Navigate to your hard drive and then "Bethesda Software."
Double-click "Fallout: New Vegas" in the "Bethesda Software" folder.
Open the "NVSE" folder on your desktop and select all of its contents.
Drag those files into the "Fallout: New Vegas" folder and select "Replace" when prompted.
Open the "Fallout: New Vegas Mod Manager" and click "Launch NVSE" to load the script extender.
The NVSE will not run unless your "Fallout: New Vegas" software has been fully updated. Otherwise, you will have to run it through a Steam version of "Fallout."