The e-mail domain you have entered is already registered in the system.
This is the Company Registration form, not a User Registration form.
Employees do not have to register to use the system, the company HR Director creates user accounts for employees, at which point employees receive an e-mail with instructions on how to sign-in and use the system.
If this is a NEW company registration, click the Register Company Button. Otherwise click Cancel, and contact your HR Director to have a user account created. We'll take you to the sign-in page.