In the comments of this page:

http://msdn.microsoft.com/en-us/library/12s31dhy.aspx

..it says that TransmitFile() cannot be used with UNC shares. As far as I can tell, this is the case; I get this error in Event Log when I attempt it:

TransmitFile failed. File Name: \\myshare1\e$\file.zip, Impersonation Enabled: 0, Token Valid: 1, HRESULT: 0x8007052e

The suggested alternative is to use WriteFile(), however, this is problematic because it loads the file into memory. In my application, the files are >200MB, so this is not going to scale.

Is there a method in ASP.NET for streaming files to users that's:

• scalable (doesn't read entire file into RAM or occupy ASP.NET threads)
• works with UNC shares

Mapping a network drive as a virtual directory is not an option for us. I would like to avoid copying the file to the local web server as well.

Thanks