Sorry, not cracked the problems listed at the end of my last 64 bit dev blog. But added a new one. My BizTalk project required the reading of data from an Excel spreadsheet – don’t ask…. Now previously I have used: the Microsoft.ACE.OLEDB.12.0 provider. This allows you to treat the spread sheet as any normal data source. See sample below 1: string strConn = "Provider=Microsoft.ACE.OLE... + "Data Source=E:\\DEMO\\FileLocs\\... + "Extended Properties=Excel 12.0;"; 2: DataSet ds ......