I get an error message that the serial number and or registration code are incorrect while trying to do a custom install of Chem3D.
There is a bug in the installer that will not allow you to custom install Chem3D. In most cases, simply using the Easy install to install the entire package will be fine. In other cases, you may need to install the software to a separate folder, so as not to overwrite a more capable version of ChemDraw. Once you install to a separate folder, you can delete the less capable version of ChemDraw.