Hi Ruben,
The "Failure to Launch Excel Application" message implies that Excel may not be installed on the failing nodes. Did you install Excel 2010 x64 on all your compute nodes? Workbook offloading requires Excel on all the compute nodes while UDF offloading only
requires Excel on the client, so the diagnostic results you're seeing would make sense if that is the problem.
The other items I would verify are whether the enterprise edition of the HPC pack was installed on all nodes and whether Excel can be run manually.
Lastly, if the above items all check out, you could write a quick C# program using the ExcelDriver API directly and try to run it on one of the failing nodes, which should give you more detailed exception information about whether the error is rooted in
loading assemblies, finding the Excel executable, or something else. You can find API documentation for ExcelDriver here:
http://msdn.microsoft.com/en-us/library/microsoft.hpc.excel.exceldriver(v=VS.85).aspx And a link to the SDK download here:
http://www.microsoft.com/downloads/en/details.aspx?displaylang=en&FamilyID=bc671b22-f158-4a5f-828b-7a374b881172
Jeremy