Haram
Alcoholic intoxicants are prohibited in Islam. Khamr is the Arabic word for alcoholic drinks that cause intoxication. The Prophet declared that the prohibition was not only placed on wine, but the prohibition also included beer and other alcoholic beverages that intoxicate a person. The Prophet also forbade the trading of these intoxicants, even with non-Muslims. It is not permissible for a Muslim to import or export alcoholic beverages, or to work in or own a place that sells these intoxicants. Giving intoxicants as a gift is also considered haram.
Khamr
As far as the prohibition of alcohol in the Koran is concerned alcohol was prohibited after an incident which is recorded in the Sunni hadith literature in a hadith found in "Jami a Tirmidhi" where some companions of the Islamic prophet, Muhammad, were guests at a meal and drank wine and verses of the Koran were revealed. The narrative is found in "Chapters of Tafsir Vol.5 Book 44 Hadith No. 3026."
""Narrated Abu 'Abdur-Rahman As-Sulami: that 'Ali bin Abi Talib said: "'Abdur-Rahman bin 'Awf prepared some food for which he invited us, and he gave us some wine to drink. The wine began to affect us when it was time for Salat. So they encouraged me (to lead) and I recited: 'Say: O you disbelievers! I do not worship what you worship, and we worship what we worship' - so Allah, Most High, revealed: O you who believe! Do not approach Salat when you are in a drunken state until you know what you are saying (4:43).""