Export datatable/dataset to excel/csv file quickly A requirement for use - a get an IgalDAL project beforehand The DLL has 2 classes - Export2Exl and Export2Csv . Excel file is made especially to export large amounts of data in just a seconds. A prerequisite for Export2Exl is Excel app and sql server. Both classes can get a Datatable or DataSet. Transferring a Dataset with several datatables in it will produce a same number of excel sheets. The name of each sheet will be the same as a name of a DataTable. In CSV version - several files with adding a number after each. A use can be very simple: int m_exported = 0; Export2Exl XlUtil = new Export2Exl(PublicModule.sConnection); m_exported = XlUtil.ExportToExcel(dt); this will open excel application and import a data into it. there're option to give a filename - XlUtil.XlFileName, or just XlUtil.SaveFile ([filename]) XlUtil.SilentOpen = true will just save a file opening an application in a background. BTW, closing Excel is smooth and doesn't leave shaddows in Windows task manager. XlUtil.SuppressFileIfEmpty = true - will automatically check if a datatable is empty and won't create a file. XlUtil.CheckFileAndFolderPermissions([RemoveOldFile:false]) - for cases when creating the same filename, and check if there's a permitions for file/folder. Exceptions got: Illeagal character, No writing permissions for directory, Directory doesn't exits, Error deleting file Probably is opened. XlUtil.AppendToFile - in case a file is already exists.