If I turn off all Add-Ins, then there is no problem opening any file from the Windows Explorer. I tried this also with the other Add-Ins, but then Excel comes with an error that for example FUNCRES.XLAM is not a valid add-in. This 'reinstallation' seems to have solved one ghost instance of Excel. Location (C:\Program Files (x86)\Microsoft Office\root\Office16\Library\SOLVER) and selected the file 'SOLVER.XLAM'.
In the Excel Add-Ins list I turned off all the Add-Ins and then selected the Solver Add-In (not checkmarking it) and clicked on Browse, went to it's Now in the screenshots you'll see three open empty instances of Excel. Unless you tell me that it does of course -) We do have some DCOM entries in Event Veiwer here and there but I don't think this has something to do with this issue. There are no events to be found in the Event Viewer pertaining to Excel. When we log on as local administrator, on any computer, we don't have any problems and can start a file directly through Windows Explorer and see only one instance being opened with all the add-ins loaded and working. We also created a new user and logged on with this account on a freshly installed computer and checked again, the same issue arises. We tested this also on other systems, turning on the Analysis Toolpak + Analysis Toolpak VBA + Solver Add-In and all of our systems show this problem but this person is in fact the only one who uses these add-ins. Excel opens the file and the user can work and close the only open instance of Excel. If we open Excel FIRST and then open a file through the Windows Explorer there is no problem at all. He is able to close his file, but the other instances can only be closed through the Task Manager, or by going in each of these instances to File in the ribbon and open another file and then close the Excel window - rinse wash repeat for the other instances. Shows the contents of the file he has just double-clicked on. Then he sees Excel being opened but as soon as the Add-Ins are loaded he sees multiple Excel instances being opened by the system. He opens an Excel-file from a network location through the Windows Explorer. We are coming from Windows 7, Office 2010 and the problem that just arose has not happened before. He creates reports and uses data analyze-tools in Excel to get the data he needs.
We've implemented Windows 10 with Office365 (C2R) throughout our organization this summer but we are running into troubles with our last colleague who uses Microsoft BI.