Describes the new and improved features of Microsoft Windows Installer 4.5. The article also discusses the issues that are addressed from earlier versions of Windows Installer.

If the Windows Installer engine is corrupted, disabled, or installed incorrectly, this may cause program installation issues. Use the following methods to identify any Windows Installer issues that may be causing problems when you install, uninstall, or update programs.

Open the Office folder in the virtual drive, and then select either the Setup32.exe to install the 32-bit version of Microsoft 365, or Setup64.exe to install the 64-bit version to begin the offline installation.

Use the 32-bit installer if you’re using a 32-bit version of Windows and the 64-bit installer with a 64-bit version of Windows. To determine which version of Windows you’re using, follow the steps in Method 1 or 2.

Upgrading from the 32-bit version to the 64-bit version of Windows requires that you reformat your hard disk, install the 64-bit version of Windows, and then reinstall everything else that you had on your device.

If you can’t install, uninstall, or update a desktop program in Windows 10, the Program Install and Uninstall troubleshooter can automatically fix common issues such as corrupted registry keys or incomplete uninstall data.

You won't be able to have both the 32-bit and the 64-bit OneDrive on a device at the same time. You can seamlessly update from 32-bit to 64-bit OneDrive by downloading and running the installer.

To install either the 32 or 64-bit version of Microsoft 365, Office 2021, or Office 2019, follow the steps in Install Office on a PC. Important: If you install the 64-bit version, but want the 32-bit version instead, you must first uninstall the 64-bit version before installing the 32-bit version.

Learn how to install, reinstall, or activate Microsoft 365 or Office 2024 on a PC or Mac.

The Microsoft 365 Access Runtime files are available as a free download in either the 32-bit (x86) or 64-bit (x64) versions in all supported languages. Decide which bit version you need.