Excel 2007 automation on top of a Windows Server 2008 x64

今天在一个客户这边出来一个windows service的问题。这个service需要启动excel程序，并且对一些excel文件做一些操作。
环境是：windows server 2008 x64+Excel 2007
总是报告错误：(类似下面这样）
Service cannot be started. System.Runtime.InteropServices.COMException (0x800A03EC): Microsoft Office Excel cannot access the file 'c:/temp/test.xls'. There are several possible reasons: • The file name or path does not exist.
• The file is being used by another program.
• The workbook you are trying to save has the same name as a currently open workbook. 代码怎么看都是可以的，反复调试了service,问题最后解决了，大致有如下几点  

第一步：在服务器添加有关的一个目录

这个方案参考了http://social.msdn.microsoft.com/Forums/en-US/innovateonoffice/thread/b81a3c4e-62db-488b-af06-44421818ef91?prof=required This solution is ... ・Windows 2008 Server x64
  Please make this folder.   C:/Windows/SysWOW64/config/systemprofile/Desktop ・Windows 2008 Server x86   Please make this folder.   C:/Windows/System32/config/systemprofile/Desktop   ...instead of dcomcnfg.exe. This operation took away office automation problems in my system. A Desktop folder seems to be necessary in the systemprofile folder to open file by Excel. It disappears from Windows2008, Windows2003 had the folder,
and I think it cause this error. I think it is safer than "registry hack". If you try this solution, please let me know results.  

第二步：设置服务与桌面交互

 

第三步：关闭服务器的UAC（这一步至关重要，调试了一个下午，就是因为这个问题卡住）