EndNote includes more than 6,000 individual bibliographic styles. By default, only the most popular styles are stored as individual files in the Styles folder in your EndNote folder.
You can download additional styles from the EndNote website. Browse or search for the desired style and download it. When you open the downloaded file it should open in EndNote. Next, save the opened style (File > Save As). You should now be able to export citations in the newly installed output style.
For additional help with EndNote at Virginia Tech's University Libraries, contact endnote-support-g@vt.edu. Please include a detailed description of the problem you're experiencing, as well as any screenshots of the error.
EndNote has an extensive user support system, including technical support, a user community, and a knowledge base. Visit http://endnote.com/support for a variety of support options.