>Common practice in this kind of scenario is for the server to buffer/build the incoming file to a temp file in a temp file folder. Only when the upload is complete is that file copied out to the desired destination name and folder.

Yes, but in this case, we cannot control this as this is sent from a client.

>I *think* in that case the server will write the destination file right away with length 0, to prevent any other process from potentially creating a file with the same name in that folder. That "dummy" file will have a datetime. I don't know if the final copied file will have that same datetime, or the datetime of completion of the file upload/creation in the temp folder.

That is a good question. I will have to upload a file of 100 MB,and use Windows Explorer to see how it detects those properties during the time the transfer is in progress.