https://forums.gentoo.org/viewtopic-t-714345-start-0.html
The post from there
To make it all work right, you need to twiddle the following configuration settings:
Terminal → Keyboard:
Change the sequences sent by: The Functions keys and Keypad:
Select Linux.
Window → Appearance:
Font settings:
Pick a font that contains the Unicode line drawing characters, such as Andale Mono or Lucida Console. (Unfortunately Vista’s gorgeous new Consolas font does not have those.)
Window → Translation:
Character set translation on received data:
Select UTF-8.
Adjust how PuTTY handles line drawing characters:
Select Use Unicode line drawing code points.
Connection → Data:
Terminal details: Terminal-type string:
Enter “linux”.
Now line drawing characters should show up as they are supposed to.
