disable file downloading

...???... Is this on a website, intranet, file server? Need more information.

Sorry. A file server

in reality, you can't control the file once it leaves your server. i.e. if it is a text file, or other non-streaming media. there are ways to disable save in .pdfs and mpegs but these can be easily gotten around. Simply screen capture can save them, as can other means.

for streaming media, still not foolproof but reasonably good ways, meaning they can play file but not save it.

Ok. I am talking about a plain ordinary file sitting on my server. I want to allow user to read the file but not to download it off the server or save it anywhere. This is not web stuff. There must be a program out there that will stop downloads across a network?

What type of file? Text, Document, Executable? Specifics please....

However, on a Windows network it is not possible. Once you give users/groups rights to view a file they can download it, or do what they please with it. Even if they can view the file they could save it.

The only way to lock a file, as you say, is to restrict access to it or require a license to view or use the information.

AFAIK, there is no 3rd party application available to restrict allowed users to download a file.