Islam means to submit your will to the Will of Allah Almighty.
Allah has created this world and all human beings and sincethe day
the first human being was born and submitted his will to that of
Allah, Islam has been there. It is not correct to say that Islam
came about at the time of prophet muhammed (peace be upon him).
Whosoever believes in One God and follows his commandments is in
the circle of Islam, whether they chose to declare it or not. All
the books before the Quran, were the Islamic guidance from Allah.
They taught nothing but goodness, and so does the Quran, the last
revelation of God to all human beings. So, Islam has its origins in
the beginning of the creation of mankind, and all creatures.