try like this,
if any issues post a comment.
i assume you will get issue on the choosing the correct provider in connection string..as i don't know which version of excel u r using...
private void button1_Click(object sender, EventArgs e)
{
string connString =
"Provider=Microsoft.ACE.OLEDB.12.0;data source=C:\\excelFileName.accdb";
DataTable dataTableRes = new DataTable();
using (OleDbConnection conn = new OleDbConnection(connString))
{
OleDbCommand cmd = new OleDbCommand("SELECT * FROM SheetName", conn);
conn.Open();
OleDbDataAdapter adapter = new OleDbDataAdapter(cmd);
adapter.Fill(dataTableRes);
}
dataGridView1.DataSource = dataTableRes;
}