Office: Instabilities/crashes due to C2R and MSI parallel installation?

[German]A short note for administrators who try to run Office modules in their environment both as Click-n-Run and MSI installations. This can lead to unstable Office installations, as I just learned from feedback from blog readers.


Office C2R and MSI parallel installation

Microsoft usually offers its Office suite as a click-to-run installation (some explanatory information can be found here). A web installer then takes all the components of Office and sets them up on a target system. Works only as long as Microsoft offers the download.

But there is also an Office professional version for companies that can be installed via .msi files. The advantage: You have the installation files for the Office package on a DVD or on your hard disk and can install in one go, without downloading. 

However, Microsoft does not provide for a parallel installation of these two product variants. This leads to the fact that many an administrator in company environments runs into problems. If one variant is installed and the other variant is needed for an Office module, this is not possible.

But in the blog post Install Office Click-n-Run and MSI version on same machine I had described a way in July 2018 how a parallel installation is possible. The approach was described in a discussion thread on Technet and seems to work. 

Instabilities due to C2R and MSI parallel installations?

Unfortunately it seems that C2R and MSI parallel installations lead to stability issues with Office modules, especially Microsoft Outlook. German blog reader J.-H. Müller already pointed out this fact in this comment in Sept. 2019. Here is my translation.


I installed Office 2016 on my computer as a volume license and wanted to install MS Project 2016. At first it did not work or the MS Project could not be installed. With the registry hack it worked and I thought everything was ok now.

But the problems came later, which showed that Outlook became very unstable and certain attachments could not be loaded without a program crash. Also the repair of Office 2016 could not be done with the reference that there would still be the MS Project.

The problems got worse and worse, so I finally uninstalled the MS Project and repaired MS Office. This worked again and Outlook was running normally again.

I believe that some important files (DLLs) were overwritten during the installation of MS-Project, which caused the instability in Outlook. MS-Word and MS-Excel were not affected by the above mentioned problems.

So: as much as I was happy about the registry hack, it cost me a lot of time due to the problems. So be careful!

In the discussion area of my German blog, blog readers Beat and Obert have confirmed this fact. And this Englisch comment also reports, that Outlook even won't launch after a parallel install (only in save mode). Another users reports Skype issues (and some more users confirmed). So keep the above information in mind and be careful with parallel installations. If you have problems, just uninstall a component. Maybe it helps.

Cookies helps to fund this blog: Cookie settings

This entry was posted in issue, Office and tagged , . Bookmark the permalink.

Leave a Reply

Your email address will not be published. Required fields are marked *