I am not sure that I can even explain this problem well. Whenever I try to install software, or run my "Mackeeper" virus protection software, a box pops up. Inside this box, there are two empty "bars". There is no writing anywhere at all on the box, but it appears that it's wanting me to enter a username and password in each of the bars. (They look like those types of bars). Below there are two buttons. One is highlighted blue. When I try to enter information into the bars, then click the blue button, the box shakes as though it's saying that I didn't enter the right information. When I click on the other box, it becomes highlighted blue and the box disappears. I am assuming this is the cancel button but again, there's no writing. Additionally, when I try to type into the bars, it won't show up what I am typing. Therefore there's no writing anywhere in the box nor will it show what I'm trying to type. I called Apple today and they ran a diagnostic test remotely on my computer. He said that they found a problem in my operating system and that he'd have to transfer me to a Tier 2 technician who could repair it remotely. However, I have no software protection for my computer. Therefore, I'd have to pay to have this done and I can't afford the price. I'm hoping someone can instruct me what to do myself. My computer isn't even a year old so I'm pretty sick about this. Thank you!!