If the uploaded raw files can be transferred to .csv or .psv files, it should be a good solution. I use SSIS to handle many complicated .csv and .psv uploading procedures very successfully. Yes, in many cases, you can use 32 bit version DTExec.exe from 64 bit environment to handle the simple Excel spreadsheets (a pure tabulate format) by using SSIS. But it's not easy to handle a multi-sheets and free form format (for example, it contails titles, header or some formulated cells) Excel files. You need to access the data in a specific sheet and range in that .xls files. I think the CLR and sp_OA series OLEDB automation system stored procedures could be the ultimate solutions, if you need to work on the Excel file in very details such as sheet by sheet, range by range and cell by cell.