When inserting an Office 2013 DVD or mounting an ISO, running the root setup.exe often defaults to the 32-bit installer. To ensure you install the 64-bit version, open the disc directory, navigate into the folder explicitly named x64 , and execute the setup.exe found inside that specific folder.

Can address up to 8 Terabytes (TB) of virtual address space. This allows the applications to utilize all available physical RAM installed on modern hardware, preventing memory exhaustion when processing enormous data files. The Underlying Engine

Microsoft optimized Office 2013 64-bit for specific workloads. You should choose the 64-bit installation if your workflow includes: Enterprise-Scale Excel Modeling

For most, Office 2013 was about the new "Modern UI" and cloud integration with OneDrive . But for the power user—the financial analyst with spreadsheets spanning hundreds of thousands of rows or the database manager handling massive Access files—the 64-bit version was a necessity.

You must source 64-bit native compilations of these add-ins from the third-party vendor. Common legacy controls, such as the MSComCtl2 (Calendar control), do not have native 64-bit equivalents and will break forms in Access and Excel. Updating VBA Code for 64-Bit Address Space