You’ll need Windows 7, Windows 8 OS, or Mac OS X version 10.6 or later to successfully run Office on your PC or Mac. Office Mobile can be installed on Android phones and iPhones. Note that Office Mobile is already available on Windows Phones and does not count toward the 5-device limit.
Office 365 Enterprise supports Windows Vista and Windows XP for most web-based functionality. However, it does not support the download and use of the latest version of Office software, and you cannot substitute Office 2010 for the latest version. You can connect your existing Office 2010 and Office 2007 software to the Office 365 service.
You can install Office applications including Word, Excel, PowerPoint and Outlook on your Mac. The applications available for Mac users and the version numbers may be different from those available for PC users.
Current Office application versions for Office 365 are Office 2013 for Windows and Office 2011 for Mac. Customers with an active subscription will be entitled to the newest versions when available.
Internet access is required to install and activate all the latest releases of Office suites and all Office 365 subscription plans.
For subscription versions of Office including Office 365 Home Premium you will need to go online to manage your subscription account, for example to install Office on other machines, or to change billing options. You will also need to connect to the Internet regularly to keep your version of Office up-to-date and benefit from automatic upgrades.
Internet connectivity is also required to access the Office 365 cloud services such as SkyDrive.