Excel 2016: double-clicking on a file opens two Excel windows

I noticed this too. It must be a bug. It's rather irritating because closing the blank window closes the workbook instead. Hopefully it'll be corrected soon in an update.

For the moment, it's better to start Excel first, and to open workbooks from within Excel.

Below works in upto Excel 2013. See whether it helps in Excel 2016 or not.

Option 1 -  Please look into C:\Users\User_Name\AppData\Roaming\Microsoft\Excel (replace user name with your user name, you can directly reach here by copy and pasting following without quotes in Explorer address bar - "%appdata%\Microsoft\Excel\XLSTART") and see if is contains few files / folders. Move those files to some other location (i.e create a backup of those files / folders and delete all files / folders from here). Hence, make Excel folder blank.

Now open the file and see if the problem disappears or not. 

Note - to find Excel path, you need to find XLSTART path. Excel folder contains XLSTART folder in itself.

1. Open Excel
2. ALT+F11
3. If Immediate Window is not visible, type CTRL+G. Same can be also be accessed through View > Immediate Window
4. Type "? application.StartupPath" without quotes and press enter
5. You will have your path below.

Option 2 - One user reported - I was also having this intermitttent issue and I found out that it is related to the Explorer preview pane. It only occurs if the preview pane is open and the xls file was never selected. Double clicking on the xls file opens 2 instances of excel (one empty). The second instance is probably the one used to show the file in the preview pane. Once the file have been seen at least once in the preview pane(during the current session)  the issue does not occurs, anymore (until reboot and/or some time has elapse. I guess there is some sort of caching). TURN OFF THE PREVIEW PANE IN WINDOWS EXPLORER. If the preview pane is a must, you can right click and 'open' the document and not get the issue.

Option 3 - Sometimes, add-ins can cause problems. To determine, if add-in is a problem start Excel in safe mode and see if problem has gone away. If yes, then start Excel normally and disable add-ins one by one and start Excel again every time you disable an add-in to determine the culprit add-in.

To start Excel in Safe Mode -

Hold CTRL key and click on Excel icon

OR

In the Search Box above Windows icon, type "Excel /s" without quotes and enter.

Option 4 - Review the KB articles - https://support.microsoft.com/en-us/kb/2758592 and https://support.microsoft.com/en-us/kb/2779852

Option 5 - How to prevent files from opening automatically in Excel - http://support.microsoft.com/kb/826922/en-us

Option 6 - Login to Windows with a new user profile and run Excel.

I do -- intentionally -- have a file called PERSONAL.XLSB in C:\Users\sto\AppData\Roaming\Microsoft\Excel\XLSTART that contains my personal macros.

It seems other folks had the same issue with Excel 2013 see http://answers.microsoft.com/en-us/office/forum/office_2013_release-excel/how-do-i-hide-excel-personal-worksheet-on-startup/58b6737c-6b20-45f1-a3db-d006cf538669

How do I get Excel not to open a window for that macro-only startup document?

Hello Vijay,

Your option 1 works for me in Excel 2016. If I move my personal macro workbook out of the XLSTART folder, the problem disappears. But that is not an acceptable solution, of course: PERSONAL.XLSB is a legitimate item, and many users (including me) rely on macros in this workbook. And I definitely did not have this problem in Excel 2013.

If I remember correctly, there was a comparable problem in the initial release of Excel 2007. Microsoft should correct this ASAP.

Same here: I rely on the macros in PERSONAL.XLSB