How to Install Microsoft 365: A Complete Step-by-Step Guide

Whether you are setting up Microsoft 365 (formerly Office 365) on a brand-new computer or reinstalling it on an existing machine, getting your apps up and running is a quick process. Microsoft 365 gives you access to premium productivity tools like Word, Excel, PowerPoint, and Outlook.

Follow this definitive installation walkthrough for Windows and Mac computers.

Before You Start: Check Your Account

Before downloading anything, ensure you have an active Microsoft 365 subscription or a valid product key linked to your Microsoft Account. If you bought your subscription directly from Microsoft, the license is already tied to your email login.

Part 1: Downloading Microsoft 365 (Windows & Mac)

1. Go to the Portal: Open your internet browser and navigate to account.microsoft.com or login.microsoftonline.com (if using a work or school account).
2. Sign In: Enter the email address and password associated with your Microsoft 365 subscription.
3. Find the Install Option: Once logged into your dashboard dashboard, look for the Install apps button (usually located in the upper right-hand area of the home page).
4. Choose Your Version: Click Microsoft 365 apps to begin downloading the default installation file.
   • Note: If you need a specific language or a 32-bit version instead of the default 64-bit version, click Other options to customize your package before downloading.

Part 2: Installing on Windows

1. Run the Installer: Once the download completes, open your browser’s download folder and double-click the file named something like Setup.X64.exe or OfficeSetup.exe.
2. Approve Changes: A User Account Control (UAC) prompt will pop up asking, “Do you want to allow this app to make changes to your device?” Click Yes.
3. Let the Installation Run: An office graphic will appear on your screen saying “We’re getting things ready.” The installer will download the full suite of programs in the background. Keep your computer connected to the internet and do not shut it down during this process.
4. Finish Up: Once completed, you will see a confirmation screen stating, “You’re all set! Office is installed now.” Click Close.

Part 3: Installing on macOS

1. Open the Package: Once the download completes, open your Finder app, navigate to your Downloads folder, and double-click the Microsoft_Office_Installer.pkg file.
2. Navigate the Setup Wizard: On the initial installation screen, click Continue. Review the software license agreement and click Continue, then click Agree.
3. Choose Installation Type: Select how you want to install the software (the default settings are recommended) and click Install.
4. Authenticate: Enter your Mac’s login password or use Touch ID to authorize the software installation.
5. Complete: The installer will copy the files to your Applications folder. When it finishes, click Close. You can safely choose to move the installer package to the Trash when prompted.

Part 4: Launching and Activating Your Apps

Now that the software is installed on your hard drive, you just need to open it and link it to your license.

1. Open Word or Excel from your Windows Start Menu or Mac Launchpad.
2. A splash screen will open welcoming you to Microsoft 365. Click Get Started.
3. Sign in using the exact same Microsoft Account email address and password you used to download the software in Part 1.
4. The system will sync your digital license activation automatically. Click Start Using Word, and your setup is officially complete!