Downloading to a specific drive

My users must download a program from the interwebs to a microSD card, which can be any drive letter from A-Z.

Q: Is there a drop dead simple approach to downloading a file to a specified drive/directory without relying on the user to navigate for me? I can populate the directory with a seed file if necessary to let my program know the right home.

Example: FileName: This_is_it.txt (This let's me know this is the right folder).

FileName: Program.prc (this is the program that开发者_开发技巧 I need the user to download and place into this folder).

I don't know AIR yet, but I think AIR might be a solution, so that's why I'm putting the AIR tag on this question.

Using AIR requires your users to install its runtime, is it acceptable? Then they must install and run your program. The smoothest install process is so-called badge install, where AIR application runs installer right from the browser. You want "drop dead simple" approach for your users or for you to develop? AIR programming is simple, but not to this degree. And yes, if user gets your AIR app running, it can enumerate drives, check contents, download and write file into any location.

In HTML at least, the simple answer is no.