This error happens because Windows can’t find the Tailwind CLI command. The fix is: delete node_modules and package-lock.json, then run npm install again. After that, install Tailwind with npm install -D tailwindcss postcss autoprefixer and run npx tailwindcss init -p. If it still doesn’t work, use npx --package tailwindcss tailwindcss init -p which will download and run Tailwind directly. Also make sure you are using Node.js version 14 or higher. Once the config files are created, just add the Tailwind directives in index.css and import it in index.js to start using Tailwind in React.