not sure if Informix's OleDB Data Provider works with ADO.NEThttp://www14.software.ibm.com/webapp/download/search.jsp?go=y&S_TACT=&S_CMP=&s=&q=informixyou can always use ODBC .NET Data Provider: http://msdn.microsoft.com/library/default.asp?url=/downloads/list/netdevframework.asp
http://msdn.microsoft.com/library/default.asp?url=/downloads/list/netdevframework.asp