Ok so heres the deal, I plugged in an external hard drive into my imac. then all the sudden it froze. I restarted it and all my desktop icons are gone, I cant open finder or the trash. The bar at the top of the screen that has the time is gone/ I have no idea what happened, or how to fix it. So if you have the answer, please be patient and speak like your talking to a child haha I am not a computer guy. Thanks