Microsoft Office 64 bit editions

64-bit processors are very much the standard for new workstations, and using a 64-bit operating system like Windows 10 64-bit allows a user to make use of more system memory if it is available. For example a 32-bit operating system can only use the first 3GB of memory in a system. To use any more than this requires a 64-bit operating system.

Many users are now taking advantage of these benefits, and since Office 2010 was released with a 64-bit option, it may seem logical to opt for the 64-bit version of Office as well.

However, even Microsoft are warning that careful consideration must be taken into account before installing a 64-bit of Office.

The recommendations for which edition of Office to install are as follows:

  •  If users in your organization depend on existing extensions to Office, such as ActiveX controls, third-party add-ins, in-house solutions built on previous versions of Office, or 32-bit versions of programs that interface directly with Office, we recommend that you install 32-bit Office (the default installation) on computers that are running both 32-bit and 64-bit supported Windows operating systems. 
  •  If some users in your organization are Excel expert users who work with Excel spreadsheets that are larger than 2 gigabytes (GB), they can install the 64-bit edition of Office. In addition, if you have in-house solution developers, we recommend that those developers have access to the 64-bit edition of Office so that they can test and update your in-house solutions on the 64-bit edition of Office.


No support is provided for side-by-side installations of 64-bit and 32-bit editions of Office, including across applications. For example, there is no support for side-by-side installations of the 2007 Microsoft Office system 32-bit with Office 2010 64-bit, or for Microsoft SharePoint Workspace 2010 64-bit and Microsoft Excel 2010 32-bit.

JCS Products are themselves tightly integrated with Office 32 bit versions. It uses a 32-bit Access Runtime, and it integrates with Microsoft Word using custom Add-Ins. We have endeavoured to enable a way that clients can use Office 64-bit version, but we cannot recommend it, as Microsoft themselves do not support this type of side-by-side installation of 32-bit and 64-bit versions of Office, and we cannot guarantee that problems may not occur in the future.

If there really is a requirement to use Office 64-bit, the following procedure must be followed 

  • Uninstall all previous versions of Office
  • Uninstall JCS
  • Uninstall Microsoft Access Runtime
  • Install Office 64-bit (this will fail if any 32-bit Office components remain)
  • Apply all updates to Office
  • Re-install the latest version of JCS.

From this point on, it will not be possible to run the Office installer again without un-installing JCS and the Access Runtime, instead, to add or remove components from Office use the "Uninstall a program" option in Control Panel, highlight Office and click on the "Change" button.