connection string for ms access 2007

I am getting error as The Microsoft.ACE.OLEDB.12.0 provider is not registered on the local machine

My code is
public string Upload(HttpPostedFileBase uploadFile)
{
StringBuilder strValidations = new StringBuilder(string.Empty);
try
{
if (uploadFile.ContentLength > 0)
{
string filePath = System.IO.Path.Combine(HttpContext.Server.MapPath("../Uploads"),
System.IO.Path.GetFileName(uploadFile.FileName));
uploadFile.SaveAs(filePath);
DataSet ds = new DataSet();

//A 32-bit provider which enables the use of

//string ConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + filePath + ";Extended Properties=Excel 12.0;";
//string connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0};Extended Properties=Excel 12.0;";
string ConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0; Data Source = " + filePath + ";Persist Security Info = False";

using (OleDbConnection conn = new System.Data.OleDb.OleDbConnection(ConnectionString))
{
conn.Open();
using (DataTable dtExcelSchema = conn.GetSchema("Tables"))
{
string sheetName = dtExcelSchema.Rows[0]["TABLE_NAME"].ToString();
string query = "SELECT * FROM [" + sheetName + "]";
OleDbDataAdapter adapter = new OleDbDataAdapter(query, conn);
//DataSet ds = new DataSet();
adapter.Fill(ds, "Items");
if (ds.Tables.Count > 0)
{
if (ds.Tables[0].Rows.Count > 0)
{
for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
{
//Now we can insert this data to database...
}
}
}
}
}
}
}
catch{ }
return "";
}
}
}