Determining your Office version – MSI vs. C2R

When investigating an issue with your Microsoft Office applications, you may need to determine whether you have the Windows Installer (MSI) based version of Office or the Click-to-Run (C2R) version of Office. These versions are based on different installation methods.

The MSI based version of Office uses Windows Installer technology, which is a traditional method of installing and updating Office. If you install Office by using MSI, you have to wait until the whole Office product is installed before you can open and start to use the product. The C2R based version of Office uses Click-to-Run, which is a Microsoft streaming and virtualization technology that allows you to open and start to use the product before the whole product is installed. Click-to-Run is the technology used to install Office 365 subscription products, while the MSI is used mainly to install the volume license editions of Office.


To find out whether your installation is MSI or C2R, in the Microsoft Office application, such as Word or Excel, go to File > Account. If you see an Office Updates section, the installation is C2R:



If there is no Office Updates section, then it is an MSI installation:



Comments (4)

  1. karen says:

    there has to be a way to open .xls files in excel 2016. I’ve read a bunch of articles about the update released today (8/9/2016) but I can’t figure out how to fix the issue. I have several coldfusion applications that output data as .xls files. I either need new code to output .cfm files as .xlsx files, or some way to open those original .xls files in Excel.

    1. Jack Kruger says:

      You can right click on the older .xls, select properties, and choose to “unlock” the document. Then, once it’s open, you can view the content. Save as a .xlsx file, and you’re good to go.

      1. Veronica says:

        The Excel 2016 is extremely frustrating because I cannot open .xls files in spite of following all the recommendations. Microsoft has got to fix this because it is not at all user friendly

        1. Tom says:

          Of course Excel 2016 can open .xls files, what are you guys talking about?

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