In order to avoid software conflict, you have to remove or uninstall any previous version of Office setup. For this, follow the below mentioned steps (Windows 10 users):
Choose Control Panel by right-clicking over the start button
Under the Programs and Features section, find and right-click your Office product
Choose Uninstall
Wait till the uninstallation process finishes
For any help or to get the solution of any error that occurs during uninstallation, contact Office helpline number. call us at: US:1-888-827-9060,