Assuming you are searching for the name John, the following procedure will search all existing columns regardless

Dim x As Integer = 0
 While x < DataGridView1.Rows.Count
 Dim y As Integer = 0
 While y < DataGridView1.Rows(x).Cells.Count
 Dim c As DataGridViewCell = DataGridView1.Rows(x).Cells(y)
 If Not c.Value Is DBNull.Value Or Nothing Then
 If CType(c.Value, String) = "John" Then
 End If
 End If
 System.Math.Min(System.Threading.Interlocked.Increment(y), y - 1)
 End While
 System.Math.Min(System.Threading.Interlocked.Increment(x), x - 1)
 End While
 MessageBox.Show("Search complete!")
 End Sub