Hi

we have moved from win2003 to win 2008/IIS7

The ASP.NET application generates excel 2003 reports, and it used to work fine, after the migration it stopped working.

I need to give permissions to Microsoft Excel Application which was missing in DCOM config on windows 2008. I did the following to give Excel permissions.

1. In DCOMCNFG, right click on the My Computer and select properties.
2. Choose the COM Securities tab
3. In Access Permissions, click "Edit Defaults" and add Network Service to it and give it "Allow local access" permission. Do the same for <Machine_name>\Users.
4. In launch and Activation Permissions, click "Edit Defaults" and add Network Service to it and give it "Local launch" and "Local Activation" permission. Do the same for <Machine_name>\Users

Press OK and thats it. now I can create the instance of Excel as follows:
oexcel = New Microsoft.Office.Interop.Excel.Application

BUT the problem is, the following code is breaking:
obook = oexcel.Workbooks.Open(mfilename)

The error from the event log is as follows:

General Information
*********************************************
Additional Info:
ExceptionManager.MachineName: M1NAPP1
ExceptionManager.TimeStamp: 25/02/2010 3:34:55 p.m.
ExceptionManager.FullName: Microsoft.ApplicationBlocks.ExceptionManagement, Version=1.0.1796.30304, Culture=neutral, PublicKeyToken=null
ExceptionManager.AppDomainName: /LM/W3SVC/1/ROOT/m1Central-5-129115366562744140
ExceptionManager.ThreadIdentity: pmotupally
ExceptionManager.WindowsIdentity: IIS APPPOOL\Classic .NET AppPool
1) Exception Information
*********************************************
Exception Type: System.Runtime.InteropServices.COMException
ErrorCode: -2146827284
Message: Exception from HRESULT: 0x800A03EC
Data: System.Collections.ListDictionaryInternal
TargetSite: Microsoft.Office.Interop.Excel.Workbook Open(System.String, System.Object, System.Object, System.Object, System.Object, System.Object, System.Object, System.Object, System.Object, System.Object, System.Object, System.Object, System.Object, System.Object, System.Object)
HelpLink: NULL
Source: Microsoft.Office.Interop.Excel
StackTrace Information
*********************************************
at Microsoft.Office.Interop.Excel.Workbooks.Open(Stri ng Filename, Object UpdateLinks, Object ReadOnly, Object Format, Object Password, Object WriteResPassword, Object IgnoreReadOnlyRecommended, Object Origin, Object Delimiter, Object Editable, Object Notify, Object Converter, Object AddToMru, Object Local, Object CorruptLoad)
at AgencySetup.RptAgencyCampMain.ExportToExcel(DataSe t ds)
General Information
*********************************************
Additional Info:
ExceptionManager.MachineName: M1NAPP1
ExceptionManager.TimeStamp: 25/02/2010 3:34:55 p.m.
ExceptionManager.FullName: Microsoft.ApplicationBlocks.ExceptionManagement, Version=1.0.1796.30304, Culture=neutral, PublicKeyToken=null
ExceptionManager.AppDomainName: /LM/W3SVC/1/ROOT/m1Central-5-129115366562744140
ExceptionManager.ThreadIdentity: pmotupally
ExceptionManager.WindowsIdentity: IIS APPPOOL\Classic .NET AppPool
1) Exception Information
*********************************************
Exception Type: System.Runtime.InteropServices.COMException
ErrorCode: -2146827284
Message: Exception from HRESULT: 0x800A03EC
Data: System.Collections.ListDictionaryInternal
TargetSite: Microsoft.Office.Interop.Excel.Workbook Open(System.String, System.Object, System.Object, System.Object, System.Object, System.Object, System.Object, System.Object, System.Object, System.Object, System.Object, System.Object, System.Object, System.Object, System.Object)
HelpLink: NULL
Source: Microsoft.Office.Interop.Excel
StackTrace Information
*********************************************
at Microsoft.Office.Interop.Excel.Workbooks.Open(Stri ng Filename, Object UpdateLinks, Object ReadOnly, Object Format, Object Password, Object WriteResPassword, Object IgnoreReadOnlyRecommended, Object Origin, Object Delimiter, Object Editable, Object Notify, Object Converter, Object AddToMru, Object Local, Object CorruptLoad)
at AgencySetup.RptAgencyCampMain.ExportToExcel(DataSe t ds)


Your help will be greatly appreciated,

Thanks in advance