hold down the
"alt & print screen"
buttons and then hit these keys
"r-s-e-i-u-b"
one at a time and pause for a few seconds between each one, because every time you hit a letter, your pc is saving something, and it takes it a second or two.
when you hit the last letter (b) your system should reboot and be protected from the nasties that come with a hard shutdown.
You can remeber it like this...
r - raising
s - skinny
e - elephants
i - is
u - utterly
b - boring