After installation it is necessary to approve each computer in your O&O Syspectr account. If you have unapproved computers in your account, you'll see a notification at the top of the page.
Click the "Approve Computer"-button and select the computers you want to approve from the list. In case of rejection by clicking on the "Do not approve" button, the computer will be removed from O&O Syspectr and the client will be uninstalled from this computer.