Selecting default item from Combobox C#

You can set using SelectedIndex

comboBox1.SelectedIndex= 1;

OR

SelectedItem

comboBox1.SelectedItem = "your value"; // 

The latter won’t throw an exception if the value is not available in the combobox

EDIT

If the value to be selected is not specific then you would be better off with this

comboBox1.SelectedIndex = comboBox1.Items.Count - 1;