Download SP1 for Office 2013 Language Pack (x32) .

If you have a valid product key, the most reliable way to get Office 2013 in Portuguese is to download the entire installer in that language:

The is a nostalgic but practical necessity for users stuck on Office 2013 due to legacy hardware or corporate policy. While Microsoft has removed the direct download links, the Microsoft Update Catalog remains the safest public source.

After installation, launch Word 2013:

This usually means you are trying to install a 64-bit pack on a 32-bit Office installation (or vice versa).