The Woes of Flight Simulator X Acceleration

I've had Acceleration for 3 days now, and it has managed to cause my annoyance like no other game. Every time I have wanted to install it with my genuine, licensed copy of Flight Simulator X deluxe, it has come up with 'Microsoft Flight Simulator X must be installed to install Acceleration.'

Which is obviously quite annoying.

After uninstalling Service packs 1 and 2 for FSX I realised there a probably some registry keys from the Flight Simulator Demo. I do not know exactly how the registry works, only that it is very complicated and can act as a single point of failure. So I am not too enthusiastic. Nevertheless, I shall persevere.