How to Install Microsoft Word Equation Editor
Microsoft Word 2013 already includes the Equation Editor; in fact, this useful feature has been integrated into Word since version 2007. However, it's only available in the full desktop version of Windows, so Windows RT users are out of luck. If you're editing a document created with a version of Word prior to 2007, you need to convert the file to access enhanced features of the modern Equation Editor. Note that if you're still using a version of Word prior to 2007, you need to manually install it from your Microsoft Office CD.
Using Equation Editor

The Equation option resides in the Symbols group of Word 2013's Insert tab. Clicking the "Equation" dropdown menu presents several preset arrangements, such as Binomial Theorem and Fourier Series. Clicking "Equation" inserts a blank equation box, but the Design tab offers hundreds of selectable symbols, structures and equations to help you create your formula.
Converting Older Documents

When you open an older Word document, a Convert option appears on the File tab's Info section. Clicking this option converts the file to the modern format. To save this conversion, you'll need to save the document by clicking "File" and then "Save."
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