DataGridview Generating another row on textbox text enter

You need to set the property AllowUserToAddRows to False (this can be done at design time or programmatically e.g. this.dataGridView1.AllowUserToAddRows = false;).

Your button to add the next row will need to add a row, then position the cursor for user input e.g.

int i = this.dataGridView1.Rows.Add();
this.dataGridView1.CurrentCell = dataGridView1.Rows[i].Cells[0];
dataGridView1.BeginEdit(true);