provide the needed directories inside the system profile's path.  I did this too before in 64bit but it didn't work because I was pointing to the wrong path!  I was using system32 when I should have used SysWOW64! From early one I thought it must be something related to the eco system ( folders etc ). Thanks for solving my automation problems too. It's been a while since a solution that easy solved all the problems in one pass ,) thanks for pointing us towards the Open XML Format SDK 2.0. I'm using it for a scenario where I just have to create simple spreadsheet files. The current scenario that drove this forum thread wouldn't be solved with SpreadSheetML because we're making heavy use of the calc engine/macros  in excel. AFAIK the SpreadSheetML dos not run macros etc without any full fledge excel installation, right? I've also explored that area and Office Open XML fulfills most of the requirements we need in developing our application. However, as Chris mentioned, it lacks the ability to refresh the value of a cell with a formula. (http://openxmldeveloper.org/forums/thre\\... Unless it is opened in Excel, the calculated values don't get evaluated.  Plus, it must be done on the server especially if your workbook contains Data Connections which are only accessible from the server. Unless the ability to refresh or re-evaluate Formulas and populate cells from Data Connections are available in Office Open XML SDK, it is not sufficient for our purposes. :( I am having