Sign in with the account you use for SkyDrive, Xbox LIVE, Outlook.com, or other Microsoft services.
Sign in with the account provided by your work or school to use with Office 365 or other Microsoft services.
You can install Office 365 Home Premium on up to five Mac or PC computers. You can even install it on a family member’s computer. Before you start, check the system requirements to make sure your computer can run Office.
If you’re installing on a Mac, after Office downloads, click MicrosoftOffice2011.dmg in the Downloads folder to start the installation.
If you’ve used all five installs and want to use Office on another computer, you can. But first you have to deactivate it on one of the first five computers.