What to Euro two Euro countries did not use the Euro?

A lot more than two countries in Europe do not use it. Europe consists of over 50 countries. 28 of those countries are members of an organisation called the European Union. 18 of those countries use it, so 10 of those 28 countries do not use the Euro. Those 10 countries are:

The United Kingdom, Poland, Romania, Sweden, Denmark, Hungary, Romania, Bulgaria, Lithuania, The Czech Republic and Croatia.