It appears to have installed properly but when I go to register it after putting in the code it just sits there.
Could be simply due to the fact you are trying to register in Full Screen mode and, as explained on the installation guide (fsdt_install_guide.pdf, page 15 - "Activating your serial number" ), is best to register in Windowed mode instead ?
The program hasn't probably locked up, it's just that its registration window has gone behind the FS9 main screen. This won't happen in Windowed mode.