I looking for the best sound compositor program. Which is the best ?

It depends on your knowledge.

If you have no real skill in music then you shouldn''t even attempt it.

However, if you know music, I suggest using Musicshop by Opcode. I''m not sure if there is a PC version, but it is without a doubt the best composing software there is. It''s cheap too ($100). No other program gets you going quicker.