I found a possible solution here: http://www.made4dotnet.com/Default.aspx?tabid=141&aid=15
Edit:
If you automate Microsoft Excel with Microsoft Visual Basic .NET, Microsoft Visual C# .NET, or Microsoft Visual C++, you may receive the following errors when calling certain methods because the machine has the locale set to something other than US English (locale ID or LCID 1033):
Exception from HRESULT: 0x800A03EC
and/or
Old format or invalid type library
SOLUTION 1:
To get around this error you can set CurrentCulture to en-US when executing code related to Excel and reset back to your originale by using these 2 functions.
//declare a variable to hold the CurrentCulture
System.Globalization.CultureInfo oldCI;
//get the old CurrenCulture and set the new, en-US
void SetNewCurrentCulture()
{
oldCI = System.Threading.Thread.CurrentThread.CurrentCulture;
System.Threading.Thread.CurrentThread.CurrentCulture = new System.Globalization.CultureInfo("en-US");
}
//reset Current Culture back to the originale
void ResetCurrentCulture()
{
System.Threading.Thread.CurrentThread.CurrentCulture = oldCI;
}
SOLUTION 2:
Another solution that could work, create a 1033 directory under Microsoft Office\Office11 (or your corresponding office-version), copy excel.exe to the 1033 directory, and rename it to xllex.dll.
Although you might solve the problem using one off these solutions, when you call the Excel object model in locales other than US English, the Excel object model can act differently and your code can fail in ways you may not have thought of. For example, you might have code that sets the value of a range to a date:
yourRange.Value2 = "10/10/09"
Depending on the locale this code can act differently resulting in Excel putting into the range any of the following values:
October 10, 2009
September 10, 2009
October 9, 2010
