If you want to send/receive files, try using a BinaryReader and a BinaryWriter for this.

StreamReader and StreamWriters work on text files and only on specific encodings - that's why some text files might not transfer correctly if you specify the wrong encoding. If you don't care about the content and just want to transfer them, binary readers/writers, as their name implies, will treat files as binary files, reading and writing chunks of bytes which guarantees that the file won't be misinterpreted.