The ability to drag and drop files into a SharePoint 2013 document library is a new feature that requires some Office 2013 files to be installed on your computer. To obtain these files, you can install any Office 2013 program. If your organization is not ready to roll out Office 2013 enterprise wide, you can install Lync 2013 or SharePoint Designer 2013. Because SharePoint Designer is a powerful tool, only power users with appropriate training should use it to modify SharePoint sites. Through Central Administration, farm administrators who are worried about the unauthorized use of SharePoint Designer can control—at the web application level—which users are allowed to use the tool.
After installing an Office 2013 program to enable the drag and drop to a document library feature, users may not be able to open Office files—such as Word, Excel, or PowerPoint—in the client or desktop application. This is a known issue that is resolved by installing Service Pack 2 for Office 2010. Click here for the 32-bit version or click here for the 64-bit version of the Office 2010 Service Pack 2.