You are using a URI of the form

file://foo

right?

That's as far as my knowledge goes. Sorry.

I'm on a MacOS X machine right now so I can't check it further for you
in terms of C: drives and whatnot.

Since MacOS uses a Unix filesystem, where the root starts at "/", the URI has three slashes like this:

file:///Users/user1/Desktop/SampleFile

Offhand, I don't remember how to insert the DOS style C: drive in there.

Edit:
I just got Googly with it.
Try this:
file://localhost/c:/programs/myfile.txt[\r\n]

Also, you probably don't really need the [\r\n] at the end.