Launch permissions for COM services

I have been experiencing issues when running IIreset. Looks to me like I need to add my defaultAppPool to have launch permissions for the com service.
 I go to: Command prompt->dcomcnfg->component services->computers->right click on my computer->properties.
Go to COM security
Under launch and activation permissions, but I don’t have the option to add the defaultAPPPool to the security setting, only local accounts are available. Any suggestions? 

Solution 
There you can add users only. Probably you need to add the identity of defAppPool . Go to IIS -> Application Pools -> locate defAppPool right click -> properties -> Identity -> by default it is network service . If it is some other user , just note id down.

Go to Command prompt->dcomcnfg->component services->computers->right  click on my computer->properties.
Go to COM security
And add the user here . machineName\network service or machineName\Username