The 32-bit version of Office is installed by default. Even if your computer is running a 64-bit version of Windows, we recommend that you install the 32-bit version of Office, because it is more compatible with the applications and add-ins that work with Office. If you do want to install the 64-bit version of Office, you can do so by taking the following steps: Office 365 Home Premium Preview: Go to www.office.com/myaccount, click Languages and install options, and then click Additional install options. Other Office 365 plans: Log into your account at www.office365.com and choose the option to install the 64-bit version of Office. It is not possible to install both the 64-bit version and 32-bit versions of Office on the same computer.