Support Center is intended for Home Users, not business computers. Read THIS  Many of us uninstall it since it is mostly intended for new users. For Biz Client customers attempting to migrate to DSC 3.0, you need to be aware that your systems are not supported by the software. 
I just want to verify if the following is true. Dell Support Centre only works for the:  series. There is no version that can be installed on the Optiplex Desktop series?
Dell Support Centre - Dell Optiplex incompatible system