I don't know how to explain this, but after spending all day searching for answers on internet, I found someone who had the same "brilliant" idea than me and this is how he explained it... I WAS "JUST" MESSING AROUND WITH SOME SETTINGS ON MY MAC. I RIGHT CLICKED ON MY MACBOOK HARD DRIVE ICON IN THE FINDER, AND HIT "MORE INFO". FROM THIER, I CHECKED THE "LOCK" CHECKBOX, AND THE IN THE LISTBOX BELOW THAT THIER WERE 3 NAMES, I HIT THE LITTLE LOCK ICON ON THE BOTTOM TO MAKE CHANGES TO THE LISTBOX, AND CLICKED THE "EVERYONE" TAB AND A LIST OF OPTIONS CAME UP, I DONT REMEBER THE ONES OTHER THAN THE ONE I CLICKED, WHICH SAID "BLOCK ACCESS". NOT KNOWING OF WHAT CAN REALLY HAPPEN. SHUT IT DOWN, AND THEN LATER TURNED IT ON. IT STARTED UP NORMAL SO FAR, GRAY SCREEN, APPLE SYMBOL, LITTLE CIRCLE OF LINES SHOWING THAT ITS LOADING, THEN IT GOES TO A BLUE SCREEN, AND THE LITTLE CIRCLE OF LINES STAYED THIER, AND IT WOULD STAY AT THIS SCREEN. MY GUESS IS THAT I BLOCKED ACCESS TO MY INTERNAL HARD DRIVE AND NOW IT WONT BOOT UP, BUT AT THE TIME IS SEEMED LIKE I WAS DENYING ACCESS TO ONLY THE PEOPLE THAT WERE NOT LOGGED IN. On the same post it said to check the Disk Utility and repair Disk Permissions... I tried this and it didn't work. I'm desperate. I don't know what else to try. 2 days ago I restarted my Mac and I really don't want to do that again... any idea/suggestion is more than welcome! Cheers!