Office 365 is installed as a 32-bit program on your Windows PC by default.
Microsoft recommends the 32-bit version, even on 64-bit systems, to avoid compatibility issues with third-party add-ons. However, there may be instances when you’d want the 64-bit version, like if you’re using a very large database or worksheet.
If you need the 64-bit version of Office, follow these steps:
Remember that you can’t have both the 32-bit and 64-bit versions of Office installed at the same time. If you already have the 32-bit version installed, you’ll need to uninstall it before installing the 64-bit version. For more details on the differences between the two versions, refer to Microsoft’s documentation.