🚀 Overview: Coexistence of Office 2013 (MSI) with Legacy Office Suites

For IT administrators, managing environments with multiple versions of Microsoft Office requires a strategic approach to prevent software conflicts and registry corruption. While Windows supports the side-by-side installation of Office 2013 alongside older versions like Office 2010, 2007, or 2003, Microsoft generally advises against this configuration in production environments. This documentation outlines the strict installation sequences, architectural limitations, and virtualization alternatives necessary to maintain system stability when a multi-version setup is unavoidable.

⚙️ Key Technical Details

• 🏗️ Mandatory Installation Hierarchy: To ensure registry keys, shared components, and file extensions are mapped correctly, you must install Office suites in chronological order from oldest to newest. Failure to follow this sequence will likely break file associations and shared features.
  • 1st: Microsoft Office 2003
  • 2nd: Microsoft Office 2007
  • 3rd: Microsoft Office 2010 (32-bit only)
  • 4th: Microsoft Office 2013 (32-bit only)
• 🛡️ Virtualization as a Best Practice: Microsoft recommends isolating Office versions using virtualization to bypass local file system and registry conflicts.
  • Microsoft App-V: Allows incompatible applications to run in a sandbox, preventing local installation conflicts and enabling on-demand streaming.
  • Hyper-V / Windows Virtual PC: Ideal for running legacy Office versions within a completely separate guest OS.
  • Remote Desktop Services (RDS): Can be used to host specific versions on a server, though it is critical to note that Terminal Services environments do not support multiple local Office versions.
• ⚠️ Architecture Restrictions: You cannot mix 32-bit and 64-bit architectures of Office on the same operating system. If you intend to deploy Office 2013 64-bit, all previous 32-bit Office versions must be decommissioned first.
• 📂 Binary File Locations: Office 2013 utilizes specific “Bin” folders to maintain separation:
  • 32-bit Windows: Program Files\Microsoft Office\Office15
  • 64-bit Windows: Program Files (x86)\Microsoft Office\Office15
• 🛠️ Administrative Customization: For enterprise deployments, the Office Customization Tool (OCT) can be used to modify shortcut locations. Access this by executing the following command from the installation media root:
  
  setup /admin

📦 Impact on Deployment and User Experience

📅 Outlook and Collaboration Tools: Unlike other Office apps, Outlook cannot coexist with previous versions. Installing Outlook 2013 will automatically trigger the removal of any earlier Outlook installations. Similarly, SharePoint Workspace 2010 will supersede and remove Microsoft Office Groove 2007, regardless of whether “Keep these programs” is selected in the setup wizard.

⏱️ Word Registration Delays: When multiple versions of Word are present, the application may attempt to re-register itself upon every launch, causing significant startup delays. Admins can suppress this behavior by modifying the Windows Registry, though this may impact some functionality.

To disable the “Re-Reg” process for Word 2010, navigate to the following subkey:

HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Word\Options

Create a new DWORD value named NoReReg and set its value to 1.

Note: This must be done for each version’s specific registry path (e.g., 15.0 for Word 2013).

📉 Access and OLE Objects: Access also suffers from a “repair/registration” cycle when switching between versions. Furthermore, if a user inserts an OLE object (like an Excel chart) into a document, the system will default to the latest version of the application available, which may create compatibility issues when sharing files with users on older versions.

🔧 Maintenance and Updates: When applying patches or .msp files, the “Oldest First” rule remains in effect. Updating an older version of Office often triggers a repair that resets file associations to the older version. Consequently, after updating a legacy suite, you may need to perform a “Repair” on Office 2013 via the Control Panel to regain proper file associations.

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Official Source: Read the full article on Microsoft.com