Knoppix HD Install - Small Problem re. other program - help!

[mentalalien2002]

While Knoppix was installing to HD, I accidentally opened another program, a fantasy game (I can't remember the name). The game said something, then went into a blank (but not quite black) screen.
I need to get back into the install, but there doesn't seem to be a way to close the other program. I have tried various reccommended shortcut keys, including ALT-F4, ALT-TAB, CTRL-Z and a few others i found but cannot remember.
Can someone please tell me how to quit this unwanted program, and if not, whether it is safe to reset the computer and start again (I think not)

[mzilikazi]

It's not going to hurt anything to reboot. Of course you'll have to start the install over again. Try xkill to close that window. You'll have to have access to a terminal or the menu item for Xkill tho...