Sometimes it is needed to set individual user permissions to chosen COM objects like (Excel). Here is short explanation what are these permissions and how to set them:

Dcomcnfg.exe provides a user interface for modifying certain settings in the registry. By using Dcomcnfg.exe, you can enable security either on a computer-wide or a process-wide basis. … Or you can use Dcomcnfg.exe to enable security for a particular application only.

https://docs.microsoft.com/en-us/windows/win32/com/setting-machine-wide-security-using-dcomcnfg

And here is practical example how to use it:

1. Reports generated in Excel don’t work invoked via VisualBasic Script using Windows Task Scheduler:

https://social.technet.microsoft.com/Forums/ie/en-US/3ab5066f-c8db-4cdd-9c69-add5e2e3c2ac/task-scheduler-with-excel?forum=winserverManagement

Solution:

Create folders:

C:\Windows\System32\config\systemprofile\Dektop

C:\Windows\SysWOW64\config\systemprofile\Desktop

and set up:

Add Local Launch and Local Activation permissions to the Microsoft Excel Application DCOM Config.