Technically, she does not have one, but is from the House of Windsor.
Elizabeth never uses a surname. Her dynasty is called the House of Windsor, but I think it would be perceived as a terrible insult to address her as Elizabeth Windsor.
Some background material from the Wikipedia article on Windsor:
By virtue of Queen Victoria's marriage to Prince Albert, son of Duke Ernst I of the small German duchy of Saxe-Coburg and Gotha, Victoria's descendants were members of the ducal family of Saxe-Coburg and Gotha with the house name of Wettin. Victoria's son Edward VII and his son George V reigned as members of this house. However, high anti-German feeling among the people during World War I prompted the Royal Family to abandon all titles held under the German crown and to change German-sounding titles and house names for English-sounding versions. On 17 July, 1917, a royal proclamation by George V provided that all agnatic descendants of Queen Victoria would be members of the House of Windsor with the personal surname of Windsor. The name Windsor has a long association with English royalty through the town of Windsor and Windsor Castle.
Her family name is Windsor which was changed to Windsor when she was a child. She is married to Phillip Mountbatten, a prince of Greece and Denmark.
As Elizabeth II was the daughter of King George VI, and as she chose her own name as her regnal name, her name before assuming the throne was, as it is after, Elizabeth Alexandra Mary. Do note that the Royal Family does not have a surname, thus that is her complete name.
Queen Elizabeth II is not. Queen Elizabeth the Queen Mother was.
Queen Elizabeth II's Mother was Her Majesty Queen Elizabeth Angela Marguerite Bowes-Lyon, The Queen Mother.
Queen Elizabeth II
Queen Elizabeth II Bridge was created in 1991.
Queen Elizabeth II
As Elizabeth II was the daughter of King George VI, and as she chose her own name as her regnal name, her name before assuming the throne was, as it is after, Elizabeth Alexandra Mary. Do note that the Royal Family does not have a surname, thus that is her complete name.
Queen Elizabeth's surname was Windsor. Her family's surname was Saxe-Coburg-Gotha until 1917 when they changed it to Windsor to sound non-German (the British people were anti-German then as it was WWI). Members of the British Royal Family do not have surnames. They are the descendants of the house of Windsor but this is not the same as holding a surname. However, as you posted this Question in the "Elizabeth I" category I assume you mean the first Queen Elizabeth. Elizabeth I was a member of the House of Tudor but, as with Elizabeth II this does not constitute a surname
Elizabeth Tudor Queen Elizabeth the First was from the house of Tudor so her name would have been Elizabeth Tudor. The current Queen Elizabeth the Second is from the house of Windsor, so her name is Elizabeth Windsor.
Queen Elizabeth II has not died
Queen Elizabeth II is not. Queen Elizabeth the Queen Mother was.
Queen Elizabeth II was born in 1926...
queen elizabeth II
queen Elizabeth II
Regnal numbers, I II, IV etc are only applied to the Monarch. If the Monarch's spouse is a female then she automatically becomes Queen Consort. Hence: Queen Elizabeth I, followed by Queen Elizabeth the Queen Consort and then Queen Elizabeth II. When Queen Elizabeth II ascended to the throne Queen Elizabeth became Her Majesty Queen Elizabeth the Queen Mother a title afforded to her by Queen Elizabeth II
queen elizabeth II
Queen Elizabeth II's Mother was Her Majesty Queen Elizabeth Angela Marguerite Bowes-Lyon, The Queen Mother.