Recently, software update stopped responding after I hit the "Install" button, so I had to force quit. Now, none of my applications will open- they just bounce in the dock for a while and stay there, without the dot appearing- including disk utility and system preferences (I thought it might be a repair permissions problem after poking around forums). I do not have install discs with me and plan on going to the apple store tommorrow. Finder still works, and I emptied the trash, but now clicking on the trash gives me the message that it "cannot be opened while trash is being emptied," which leads me to believe something is frozen. So, my question is: it is safe to turn off or try restarting the computer? Last time I had a problem similar to this and restarted, I got the flashing folder icon that signaled my hard drive was dead, so I am worried about letting it go to sleep or shutting down. What should I do?