I'm not surprised it doesn't work - I would be amazed (and rather saddened) if it did.
Think for a moment about what you are trying to do:
"Read file file from your local pc, and write it to a specified folder, of a specified hard drive, of a computer somewhere else in the world, via the internet."
If you could do it that easily, what would stop me doing the same? And using your remote server for an internet backup, or file sharing device? And if it filled up a bit, deleting your files to make room for mine?
If you want to do that, then you need to look at setting up an FTP connection between your software and the server (assuming it is configured to accept FTP requests) and transfer the file that way. Google can help you there - it found this:
C# FTP Client Library[
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