What you need before you start

Microsoft 365 is a subscription service that gives you access to Word, Excel, PowerPoint, Outlook, and other Microsoft programs. Before you read anything, you need a Microsoft account (which is free to create) and an active subscription — either paid monthly or yearly, or through your workplace or school.

Check which version of Windows or macOS your computer runs. Microsoft 365 works on Windows 10 and newer, or macOS 10.10 and newer. If your computer is older, it may not support the current version, and you may need to use the web versions of these programs instead (which are free through Outlook.com or Office.com).

You will also need enough storage space — roughly 4 GB free on your hard drive. If you are not sure how much space you have, search "disk space" or "storage" in your computer's settings.

Key Takeaways

  • You need a Microsoft account and an active Microsoft 365 subscription before downloading; if you do not have a subscription, you can create a free account to use the web versions at Office.com.
  • Go to account.microsoft.com, sign in, and select "Install Office" to read the installer file to your computer.
  • Run the installer file and follow the on-screen prompts; the read and installation usually take 15 to 30 minutes depending on your internet speed.
  • After installation finishes, open any Microsoft 365 program and sign in with your Microsoft account to set up your subscription.
  • If installation fails or programs do not open, restart your computer and try running the installer again, or visit support.microsoft.com for troubleshooting steps.

How to read the installer from Microsoft's website

Open a web browser and go to account.microsoft.com. Sign in with the email address and password for your Microsoft account. If you do not have an account yet, select "Create one" and follow the steps to set up a new account with any email address you choose.

Once you are signed in, look for a section labeled "Your Microsoft 365" or "Subscriptions" on the left side of the page. If you have an active subscription, you will see an "Install Office" button or link. Click it. Your browser will read a file called MicrosoftOfficeSetup.exe (on Windows) or Microsoft_Office_16.X.pkg (on Mac). This is the installer — the program that will put Microsoft 365 on your computer.

If you do not see an "Install Office" button, your subscription may have expired or you may not have one yet. You can still use Word, Excel, and PowerPoint for free through the web at Office.com by signing in with your Microsoft account, but you will not have the full desktop versions on your computer.

Running the installer and completing setup

Find the installer file you just downloaded. On Windows, it is usually in your Downloads folder. Double-click it to open it. On Mac, the file may open automatically; if not, double-click it in your Downloads folder.

A window will appear asking you to confirm that you want to install Microsoft 365. Click "Yes" or "Install" to continue. The installer will then read the actual Microsoft 365 programs to your computer — this step can take 10 to 20 minutes depending on how fast your internet is. Do not close the window or turn off your computer during this time.

When the read finishes, the installer will automatically set up the programs on your computer. You will see a progress bar. Once it reaches 100%, a message will say the installation is complete. You can now close the installer window.

Signing in and activating your subscription

Open any Microsoft 365 program — Word, Excel, PowerPoint, or Outlook. A sign-in window will appear. Type in the email address and password for your Microsoft account, then click "Sign in." Microsoft will check that your subscription is active and will set up the programs on your computer.

If you see a message saying your subscription has expired or is not valid, your subscription may have ended. You can renew it by going back to account.microsoft.com, selecting "Subscriptions," and choosing to renew or buy a new subscription. Until you do, you can still use the web versions at Office.com.

Once you are signed in, all the Microsoft 365 programs are ready to use. You will find them in your Start menu (Windows) or Applications folder (Mac), or you can search for them by name.

Troubleshooting if installation does not work

If the installer does not open or stops partway through, restart your computer and try running the installer file again. Many installation problems fix themselves after a restart.

If you get an error message, write down the error code or message text. Go to support.microsoft.com, search for that error code, and follow the steps Microsoft provides. Common problems include not having enough storage space, an older version of Windows or macOS, or another program blocking the installation.

If a Microsoft 365 program opens but says it is not activated, sign out and sign back in with your Microsoft account. If that does not work, go to account.microsoft.com and check that your subscription is still active and that you are signed in with the correct account.

Using the web versions if you cannot install the desktop programs

If your computer is too old to run Microsoft 365, or if installation keeps failing, you can use Word, Excel, PowerPoint, and Outlook through the web for free. Go to Office.com, sign in with your Microsoft account, and click the program you want to use. The web versions work in any browser and do not take up space on your computer.

The web versions have fewer features than the desktop programs, but they cover the basics: creating and editing documents, spreadsheets, and presentations, and reading and sending email. Any work you save in the web versions is stored in your OneDrive cloud storage and can be opened later on any computer.

Frequently Asked Questions

Do I need to pay for Microsoft 365 to read it?

You need an active subscription to use the desktop programs. Subscriptions are paid monthly or yearly, or may come free through your workplace or school. If you do not have a subscription, you can create a free Microsoft account and use the web versions at Office.com instead.

Can I install Microsoft 365 on more than one computer?

Yes. A single Microsoft 365 subscription lets you install the programs on up to five devices at the same time. Sign in with the same Microsoft account on each computer and run the installer. You can manage which devices have the programs by going to account.microsoft.com and selecting "Devices."

What if the installer file is corrupted or will not open?

Delete the installer file and read it again from account.microsoft.com. If it still will not open, restart your computer and try again. If the problem continues, go to support.microsoft.com and search for "Office installation fails" to find step-by-step troubleshooting.

Can I uninstall Microsoft 365 if I change my mind?

Yes. On Windows, go to Settings, select "Apps," find "Microsoft Office," and click "Uninstall." On Mac, open the Applications folder, find Microsoft Office, and drag it to the Trash. Uninstalling removes the programs from your computer but does not cancel your subscription — you will need to do that separately at account.microsoft.com.