Downloading is not a problem and the serial number should be on file with Bondware, all those records were transferred to the Bondware servers.  If you have problems reinitiating your license on the new computer then contact tech support.  If you had separate runtime folders set up on your old computer, those could be transferred intact to your new system and reimported to your software.  However, if the additional content happens to reside within the main Poser runtime then I recommend a fresh reinstallation.