How to crash CMD.EXE

dir | for %i in () do nothing

You can find an access violation in the Windows event log after crashing CMD.EXE with the above command line.  Enjoy!

how to get a list of all file types on Windows and the programs that open them

for /f "delims== tokens=2" %i in ('assoc') do @FTYPE "%i">>programs.list 2>&1