Alternatively, if installation doesn't start automatically, browse the disc to find the program setup file, usually called Setup.exe or Install.exe. Open the file to start installation.

The installation file is typically named Autorun.exe or Setup.exe, but this may vary. If you're not sure, check the Readme file in the folder for instructions about how to run the installation process.

To help with issues you might encounter when installing Microsoft 365 because of slow speeds or unreliable connections, follow the steps below that are specific to your plan. You need to be connected to the internet to download this installer file, but once that's done, you can then install Microsoft 365 offline on a PC at your convenience.

Software manufacturers can create the setup of their products to use Windows Installer to help make software installation, maintenance, and uninstallation straightforward and easy. Windows Installer 4.5 is released with Windows Vista Service Pack 2 (SP2) and Windows Server 2008 SP2.

Download and install or reinstall Office 2021, Office 2019, or Office 2016. Important: Support for Office 2016 and Office 2019 will end on October 14, 2025 and there will be no extension and no extended security updates. All of your Office 2016 and Office 2019 apps will continue to function.

Be sure you're connected to the Internet and then open any application, such as Word or Excel. In most cases, the Office or Microsoft 365 apps are activated once you start an application and after you click Accept to agree to the Microsoft Software License terms.

After October 14, 2025, Microsoft will no longer provide free software updates from Windows Update, technical assistance, or security fixes for Windows 10. Your PC will still work, but we recommend moving to Windows 11. Learn more. Note: Use these steps for Windows programs.

There are two ways to get apps from Microsoft Store: Select Start , and select Microsoft Store. From the taskbar, select the Microsoft Store icon.

Open the x64 folder in the installation root, and then double-click setup.exe. After setup completes, continue by following the default installation instructions, by entering the product key (step 2).

To change from a 32-bit version to a 64-bit version or vice versa, you need to uninstall Microsoft 365 first (including any stand-alone Microsoft 365 apps you have such as Project of Visio). Once the uninstall is complete, sign in again to www.microsoft365.com and select Install apps.