How to Make MS Excel 2010/2013 Open Multiple Instances

 1. Close all MS Excel running. Click on the Start Menu and type regedit in the search field and press Enter.

 2. Once Registry is up, under the HKEY_CLASSES_ROOT

3. Follow this path HKEY_CLASSES_ROOT\Excel.Sheet.8\shell\Open\command

4. On the right column, double-click on Default and edit the value data as shown below. Delete the \dde and replace it with "%1" then hit OK.

5. On the right column, right-click on command and choose rename. Rename it to command2 then hit Enter.

 6. On the left column, right-click on ddeexec right below command, and choose rename. Rename it to ddeexec2 then hit Enter.

7. Repeat steps 3-6 in Excel.Sheet.12

No need to reboot your computer, you can start firing up multiple instances of Excel.

Thank you for using this simple step-by-step tutorial!

Cheers!