Issue with O365 account on a machine with 2 accounts

Iron Contributor


I am having some issues that I think might be of my own making, with the O365 Accounts associated with my Office install.  I work from home and am using my own PC for both work and my own stuff.  As part of my work I am allowed to install Office Pro Plus on up to 5 devices and so have installed it on my home PC.  This used to work with no issues until I got a brand new PC in December and had to reinstall everything.  Now what happens is when I start any Office App, the user associated with the app is my personal Microsoft account.  I have to remember to press "switch account" to change to my Work user.  If I forget to do this there are a few strange side affects:-

1.  I do not see my work Onedrive and Sharepoint files in "recent" or "latest files" when I go to attach something in Outlook"

2.  Last week I managed to lock a file on our sharepoint site because I had made a change whilst my personal microsoft account was editing the document.

3.  I cannot work real time collaboratively on a document with other work colleagues


At some point I think Windows 10 asked me to associate my work account with my personal one and I said "yes" which I think is part of the problem.

The attached screenshot shows the "2 accounts" I can switch between.  Note that both have the same 2 emails associated with them, but they are reversed.  It is the bottom one that has my personal email listed first that is always the default user when I first start an office app in the morning.


So my question is can I either change something so that the top account is the one that always opens the office apps, or is there something else I need to fix and is there potentially a different way of working I should be doing to make this work?



3 Replies

Do you mean that both the work and personal accounts use the same address? If so, that's definitely known to cause problems and in fact Microsoft no longer 'recommends' such configurations:


Other than that you can re-activate Office with the work account.

Hey Mark,


The flow you're seeing is "by design" Office uses the SignedInADUser for Windows to activate/authenticate. When Office is launched on a clean machine we use the Signed in AD User. If you want to change this behavior you will break Single Sign On but you WILL be able to enter specific credentials.  Your Office apps will use the cached UPN going forward.


Please follow the steps on my blog post here to clean u the activation 


Once cleaned up crate the NoDomainUser registry key to force Office to prompt for sign in rather than using the AD User signed into Windows.

  1. Start Registry Editor.
  2. Navigate to the following registry subkey:
    Office 2016
    Office 2013
  3. Right-click the entry, and then select New.
  4. Add a new DWORD value to the registry called NoDomainUser, and then set it to a value of 1.


Please reply with any questions or concerns.

Hi Thanks for your response,  I actually manged to fix this myself in a very easy way I should have thought of first.  I simply signed out of the office app with my Windows signed in ID, which left just my work ID listed in the Office apps and this has persisted.  This is fine for me because I almost exclusively use the O365 apps on my work machine for work anyway, so have no need to switch between accounts.


I think my problem was as you had stated  i.e 

  1. I have a personal Windows PC which I have had for a long time.
  2. I installed a licened copy of Office pro plus on this machine
  3. The first time I fired it up it asked me for my work credentials to activate the software
  4. But it had already signed me in as a "user" with my Windows acount as well, so I had 2 emails registered with the software and it always defaulted to my Windows Login account (with the option to "switch accounts"), which caused these strange issues
  5. After simply "signing out" from the account page of the office app from my WIndows account, it now starts up with me Work email as my Office user as this is now the ONLY account on my Office apps