Microsoft Office 365 - Installation - How to Download and Install Office 365 Desktop Apps on Mac or Windows

Summary

This article provides step-by-step instructions for downloading and installing Office 365 desktop applications on Mac or Windows.

Intended Audience: Faculty, staff and students

This article provides step-by-step instructions for downloading and installing Office 365 desktop applications on Mac or Windows.

OSU Cowboy Mail account – A valid Oklahoma State University email account.
Internet access – To log in to Cowboy Mail and download the Office installation file.
Compatible device – A Windows or Mac computer that meets Microsoft Office system requirements.
Sufficient storage space – Enough free disk space to download and install Office.
Permissions to install software – Ability to allow apps to make changes on the computer (administrator access may be required).
Web browser – To access the Cowboy Mail portal and download Office.
No conflicting Office versions – Any existing versions of Microsoft Office must be uninstalled before installing the new version.

Go to http://cowboymail.okstate.edu/.
Sign in with your Okey email address.
After you sign in, pick the 9-dot app launcher next to Outlook in the left corner of the page.
Select More apps.
In the upper right corner, select Install apps to extend the drop down menu.
Choose Microsoft 365 apps.
The My Account windows will open.
Select Install Office.
The installer file will download to your computer.
Open the downloaded file (OfficeSetup.exe on Windows or Microsoft_365_Installer.pkg on Mac).
Follow the instructions on the screen and wait while the apps install.
When installation finishes, open Microsoft Word, Microsoft Excel, or Microsoft PowerPoint.
Sign in with your school email again to activate the apps.
Microsoft 365 desktop apps are installed and ready to use.

Article ID: 20230

Created

Mon 8/25/25 3:30 PM

Modified

Mon 3/23/26 9:45 AM