Your DOS screen graphics are font-dependent. You need an ANSI VGA screen font with linedrawing characters.

\r\n\r\n

I see this most often showing up in Linux when I switch from standard console to SVGATextMode, which has the side effect of changing screen font. Muck around a bit to find what works.

\r\n\r\n

And strong second on PuTTY.