Microsoft project management software used to plan, manage, and communicate a project schedule and other information among workgroup members, project managers, and other stakeholders.
Microsoft Project and Microsoft 365 desktop apps generally must be on the same installation platform and bitness. If the Project product being installed is not compatible with the existing Microsoft 365 installation (for example, different bit version or conflicting product type), the installer will require uninstalling the existing Office/Microsoft 365 apps first.
For Project for Office 365 (Project Online Desktop Client) in an Office 365 operated by 21Vianet environment, there are two supported options:
- Have the Microsoft 365 admin or IT department install Project Online Desktop Client. In that case, no manual uninstall is required; the admin manages the deployment so it matches the existing Office platform.
- When upgrading from an earlier standalone Project version (such as Project Professional 2010 or 2007), uninstall that older Project first, then install Project from the Microsoft 365 portal (Office 365 home page → Other Installs → Project → choose language → Install).
If the current Microsoft 365/Office installation is blocking the Project setup due to a mismatch (for example, trying to install a different bit version), the supported resolution is to:
- Uninstall the conflicting Microsoft 365 or Office installation.
- Reinstall Microsoft 365/Office and Project together in a compatible configuration (same bitness and platform) using the standard install flows.
There is no supported workaround in the documentation that bypasses these compatibility checks without uninstalling when the installer explicitly requires it.
References: