'create a connection string named con

Public sub MyForm_Load

Dim cmd as new OleDbCommand("Select * from [table name here-avoid brackets
 if required]",con)

Dim adapter as new OleDbDataadapter(cmd)

Dim table as new datatable

adapter.fill(table)

ComboBox1.DataSource = table
ComboBox1.DisplayMember = table.Columns(3).ToString 'you can use column name or even row

Public Sub ComboBox1_IndexChanged

Textbox1.tex=Combobox1.text