On a computer that is running Microsoft Windows Server 2003 with Service Pack 1 (SP1), when you use the Response.TransmitFile method to transfer a file to a client computer, the file transfer either does not start or does not succeed.
When you use the Response.TransmitFile method to transfer a file to a client computer, the Response.TransmitFile method creates a file handle and sends it to the Microsoft Internet Information Services (IIS) Web site. If Microsoft ASP.NET closes the file handle too soon after the Response.TransmitFile method sends the file handle to the IIS Web site, the file transfer either does not start or does not succeed.
This issue has been corrected in the following hotfix package:
888420 You receive an "OverflowException" error message when you specify a Content-Length HTTP header that is larger than 2 GB in the .NET Framework 1.1
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.