Many thanks for this. OK, problem solved: basically, I didn't press down CTRL first--and keep it pressed down--but now I have it sussed and the game started up fine.
As for the Codec--I still can't download it, even from your new link. I click on the file to download but nothing happens--except that the DL waiting time keeps clocking up (e.g. 5 mins, 15 mins, 30 mins etc., etc.).
Nevertheless, the game is now startable, so maybe I don't need the Codec anyway?
Once again, many thanks for the prompt reply!