i put below code at rowsAdd event of datagridview and i worked
string datetimevalue = "01/01/1900 12:00:00 AM";
try
{
for (int i = 0; i < dgvRenewalHistory.Rows.Count; i++)
{
if (dgvRenewalHistory.Rows[i].Cells["Renewal_On"].Value.ToString() == datetimevalue)
{
dgvRenewalHistory.Rows[i].Cells["Renewal_On"].Value = "";
}
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}