Everytime I try opening folders on my computer, or opening finder, it just opens into this blank box that says Window on top. I can't access any of my files. My mac won't even read USB sticks. I am so frustrated and I have already restarted my computer a million times, tried using disk utility to clean up any errors, and even wiped out my entire computer and copied and pasted my files back onto the new system. It still won't work. PLEASE PLEASE PLEASE if you have any idea what is wrong, please help!!! I have exams next week and I need some of the files for them. All advice is appreciated. Thank you.