All over the world although with different percentages to total poulation in different countries
by. Sending messengers around to different places with letters explaining what Islam is to the rulers of the different places and inviting them towards Islam
Though many websites displaying Islam.
It spread to places in Saudi Arabia and Syria
India, Africa and Southeast asia
Indonesia, West Africa, China and the Philippines
Islam first started in Makkah (Saudi Arabia), and then spread to Madina. After that, Muslims would travel around the world (the entire world), and teach people about Islam, and what it's all about.
This question needs a little history on the Muslims. Muslims have come from the Arabian parts of Asia. There many prophets were born and spread it across the land with many difficulties. It was some places like Palistine, Saudi Arabia, Madinah, Makkah and other places. Then after Muhammad (Peace be upon him) spread his part of Islam it spread through the Roman Empire all the way to Egypt so it is really hard to say exactly. Many Muslims are very peacefull like me. :-)
Islam spread to libya by other countries
Many of them embraced Islam and became very good Muslims.
for weather the people of mecca had not agriculture and mostly their business was trading. many traders came to mecca and learned Islam and spread it in world.
Islam first spread along TRADE ROUTES since merchants could often bring the religion to places too far away to effectively conquer.
A struggle or conflict to spread Islam is a Jihad