finder and desktop items keep flashing on and off
Yesterday my itunes kept quitting unexpectedly so I tried restarting my computer. When my computer reloaded, it was totally messed up. My finder toolbar at the top keeps flashing on and off and so do my desktop items. If I try to open up a program, it will open momentarily and then "quit unexpectedly" before I can do anything. I tried booting up in "safe boot" but the finder was flashing on and off in that mode as well. I do have more than one drive installed on this computer, and after the start up tone, I held down the option key and opened up my "Media 2" drive, and that worked just fine, but none of my programs are installed on that drive. FYI: it is my "Macintosh HD" drive that is giving me trouble. PLEASE HELP ME!!
G4, Mac OS X (10.4.7)