Step 1: Locate your download of Node.js, typically it is installed under C:/program files/nodejs
Step 2: Open Visual Studios and navigate to "Tools>Options"
Step 3: In the options window navigate to "Projects and Solutions>External Web Tools"
Step 4: Add new entry with you Node.js file location (C:/program files/nodejs), IMPORTANT use the arrow buttons on menu to move your reference to the top of the list.
Step 5: Restart Visual Studios and Run an npm install, against your project, from npm command window