Windows 8 Odd black box in upper left corner of screen

Well, according to the screen shot, it says "C:\program files\mediainformationaccess\updater.exe" So have a look at that file path of your C drive and find out what software/program it's for. By the looks of your desktop, I'm guessing it goes to one of the programs you've downloaded and it's trying to update the app. Or what really scares me, it could be some back door that was open by one of those downloads and a hacker has taken over your computer with some malicious code that's being executed.

Have you checked your system from any Virus, Malware, spyware, worms, trojans and so forth? I would start there and then see what programs you have downloaded and if you really need/use any of them. If not then use Revo-unsitaller Pro (it's a 30 trial but it will remove 32 and 64 bit software) to remove them completely through the advanced removal settings.