Press control alt delete
start task manager
click on processes tab
look at the list of programs that are running...
find the HP processes on the list,
highlight the HP process,
then click: "end process."
Now go down the list and end ALL the HP processes.
Turn them all OFF.
NOW open add / delete, and delete the HP printer softyware
Also, there may be an "uninstall" tool available from the HP website.