The backspace key is what you press to delete a character that you have typed.
Almost all keyboards have some kind of backspace or delete key located just
above the ENTER or RETURN key.  Most computers will either send a BACKSPACE
(^H) or DELETE (^?) character when you press this key.  If you are unable to
erase things that you have typed, and instead get a strange character
printed to your screen when you try, then your backspace key is most likely
set incorrectly.

To change your backspace key, select "Change Backspace Key" from the menu.
You will be asked to press your backspace key.  If your computer sends
something "non-standard," you will be asked to press your backspace key
again.  After that, your backspace key will be set correctly.
