There are several native ways to convert your documents to PDF without any third-party software. Method 1: Using "Save As" (Recommended)

In Microsoft Office 2010, the ability to is a built-in feature, unlike in Office 2007 where a separate add-in was required. Because it is integrated directly into applications like Word, Excel, and PowerPoint, you do not need to download an external "Save as PDF" installer from Microsoft for the 2010 version. How to Save as PDF in Office 2010

This is the most common method and preserves formatting, hyperlinks, and document metadata. Save or convert to PDF or XPS in Office Desktop apps