How to Export dataset to Excel without using any control like gridview...

There are several ways to achieve that, for example:
1) using Interop[^],
2) using OpenXML[^],
3) using ADO.NET[^],
4) using third-party tools.

Follow above links and have a look at below set of links:
Output DataSet to Excel[^]
http://social.msdn.microsoft.com/Forums/vstudio/en-US/ea02f8e8-edf5-4aca-8c74-ef3a94b5328d/export-dataset-into-excel-sheet-in-c[^]
http://forums.asp.net/t/1197704.aspx/1[^]
http://diegworld.blogspot.com/2010/09/importexport-dataset-to-excel-file-with.html[^]