Windows2003IIS asp.net写文件失败问题急！。。。

Server Error in '/' Application.
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Access to the path 'c:\windows\system32\inetsrv\btw3.tmp' is denied.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.UnauthorizedAccessException: Access to the path 'c:\windows\system32\inetsrv\btw3.tmp' is denied.

ASP.NET is not authorized to access the requested resource. Consider granting access rights to the resource to the ASP.NET request identity. ASP.NET has a base process identity (typically {MACHINE}\ASPNET on IIS 5 or Network Service on IIS 6) that is used if the application is not impersonating. If the application is impersonating via <identity impersonate="true"/>, the identity will be the anonymous user (typically IUSR_MACHINENAME) or the authenticated request user.

To grant ASP.NET access to a file, right-click the file in Explorer, choose "Properties" and select the Security tab. Click "Add" to add the appropriate user or group. Highlight the ASP.NET account, and check the boxes for the desired access.

Source Error:

Line 556:        row.Height = 40;
Line 557:
Line 558:        wbook.Save(Server.MapPath(filename));
Line 559:    }
Line 560:}

Source File: c:\HNDL\UltimateManageSystemFB\GenerateTaskSheet.aspx.cs    Line: 558

Stack Trace:

[UnauthorizedAccessException: Access to the path 'c:\windows\system32\inetsrv\btw3.tmp' is denied.]
   System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath) +2014291
   System.IO.FileStream.Init(String path, FileMode mode, FileAccess access, Int32 rights, Boolean useRights, FileShare share, Int32 bufferSize, FileOptions options, SECURITY_ATTRIBUTES secAttrs, String msgPath, Boolean bFromProxy) +998
   System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, FileOptions options) +115
   System.IO.File.Create(String path) +37
   Biff8Excel.Excel.ExcelBinaryWriter.Write(Byte[] buffer) in F:\Biff8_C#_Excel\Biff8\Excel\ExcelBinaryWriter.cs:77
   Biff8Excel.Excel.ExcelWorksheet.CreateSheetBuffer() in F:\Biff8_C#_Excel\Biff8\Excel\ExcelWorksheet.cs:228
   Biff8Excel.Excel.ExcelWorkbook.Save(String fname) in F:\Biff8_C#_Excel\Biff8\Excel\ExcelWorkbook.cs:421
   GenerateTaskSheet.TestWriteExcel(String filename, MainPrjInfo mprj, SubPrjInfo[] subprjArr) in c:\HNDL\UltimateManageSystemFB\GenerateTaskSheet.aspx.cs:558
   GenerateTaskSheet.GenerateTaskSheetCSV(String nf, String lshh) in c:\HNDL\UltimateManageSystemFB\GenerateTaskSheet.aspx.cs:54
   GenerateTaskSheet.Page_Load(Object sender, EventArgs e) in c:\HNDL\UltimateManageSystemFB\GenerateTaskSheet.aspx.cs:35
   System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) +15
   System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +34
   System.Web.UI.Control.OnLoad(EventArgs e) +99
   System.Web.UI.Control.LoadRecursive() +47
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1061

UnauthorizedAccessException: Access to the path 'c:\windows\system32\inetsrv\btw3.tmp' is denied
高手们帮忙解决一下，给文件夹添加安全账户“ASPNET”已经试过了，不行。
用同样的方法在XP里就能解决问题，很是郁闷，Why...? --------------------编程问答-------------------- 添加一个everyone呢或者user用户呢？

补充：.NET技术 ,  ASP.NET

Windows2003IIS asp.net写文件失败问题 急！。。。

Windows2003IIS asp.net写文件失败问题急！。。。