Organizations that have their organization-wide sharing access level set to Private for accounts may want to restrict users from running the Account Owner report.

Account Owner Report control whether or not all users may run the Account Owner Report. This report allows them to see all accounts, despite the private account sharing model.

To enable Account Owner Report, follow the below steps

1. Go to Setup –> Administer –> Security Controls –> Account Owner Report.

2. Check Allow all users to run the Account Owner Report check box.

To run this report, follow the below link

https://www.infallibletechie.com/2015/06/how-to-run-account-owner-report-in.html

Cheers!!!