I am coding for Excel Automation in a .NET App . And there was the stuck telling me that " Old format or invalid Type Library. Line: Microsoft.Office.Interop.Excel".

I am using Excel XP and .NET Dev Environment 7.7.3308
Microsoft Visual C# .NET 69586-335-0000007-18357.

If anyone ever solved this, plz give me some advice.

Thanks in advance.