"Open / Save" dialog asks twice

When I export a report to Excel, I am asked twice if I want to open or save the sheet.

How can I get about this?

currentSheet.PageSetup.Orientation=PageOrientationType.Landscape;

excelApplication.Save(fileName, SaveType.OpenInExcel, FileFormatType.Excel97, HttpContext.Current.Response);

That’s a problem of IE. Please install all windows patches in your client machine.

I'm employed in a larger company that does not allow IE updates unless the updates have been tested thoroughly by our security department.

Can you tell me which patch that may solve the problem, so that I can prioritize our updates?

or...

Is there a hack or workaround to solve the problem?

Sorry I don't know the exact patch for solving this problem.

In my machine, this problem occurs after I automatically update my windows. And after some days when I installed another patch, it disappeared. This happened in the year before last year.