On the domain controller, open the group policy management tool.
Create a new group policy.
Enter a name for the new group policy.
In our example, the new GPO was named: MY-GPO.
On the Group Policy Management screen, expand the folder named Group Policy Objects.
Right-click your new Group Policy Object and select the Edit option.
On the group policy editor screen, expand the User configuration folder and locate the following item.
Access the folder named System.
Enable the item named Don't run specified Windows applications.
Click on the Show button and enter the Mozilla Firefox application name.
To save the group policy configuration, you need to close the Group Policy editor.
Congratulations! You have finished the GPO creation.