Why does "cmd /k" reset/clear/delete command history?
by specifying cmd as a command, it actually launches a "cmd" within a "cmd".. which has its own process and therefore its own buffer and command history:
Hopefully this quick-n-dirty illustration I've put together will help
As Fazer87 said, the new cmd session launched by CMD /K has its own command history. I suppose the designers of CMD.EXE could have opted to make a copy of the parent history, but they chose not to.
When you use EXIT to return to the parent cmd session, you will get back the original command history.