I get a "reference is not valid" when I try to click the link it created to another file. I used the code take from you Wiki here: Adding Hyperlinks
Also, the target file does exist.
I have attached a screenshot of the error.
[C#]
//Instantiating an Excel object
Excel excel=new Excel();
//Adding a new worksheet to the Excel object
excel.Worksheets.Add();
//Obtaining the reference of the newly added worksheet by passing its sheet index
Worksheet worksheet=excel.Worksheets[0];
//Adding an internal hyperlink to the "B9" cell of the other worksheet "Sheet2" in
//the same Excel file
worksheet.Hyperlinks.Add("A5", 1, 1, "C:\\book1.xls");
//NOTE: trivial but I'll state it anyway - you need to call this - probably should update your Wiki
saveFileDialog1.ShowDialog();
//Saving the Excel file
excel.Save(saveFileDialog1.FileName,FileFormatType.Default);