When the error appears, hit the Print Screen key, open Paint, Paste the image and save it as a .png file, then post that image here.
Well, eventually Activision got back to me and its well, sorted sort of. The only way to re-load the game I have discovered is to open a dos prompt and re- install the game by changing the directory until I reach Steam. I then installed it using good old DOS! Before all this Steam and the game where removed and the entries in the registry deleted.Then I used MSconfig to turn off start-up items (not steam) and hide all Microsoft services. All this advice came from Activision. The game works but I presume I will have to try and discover what was stopping the game from launching.