While I've seen similar when hard drives fail, I don't see the make and model. Some models lock up like that when USB things are plugged in but I don't see details about the PC or what's plugged in.
Try it without any USB things.
When I boot up my computer, after it passes the bios screen, this weird little white rectangle with a smile face in it appears in the upper left corner of the screen, with nothing else on the screen, and the computer refuses to boot past it.
It used to appear occasionally when booting up in the past, but would either go away after a few seconds, or go away after pressing the enter key on the keyboard. Now, nothing will get rid of it. I am also unable to boot into safe mode or any other modes.
I took a pic of it, but unfortunately my camera couldn't get the clearest shot of it, so I had to draw the face on the pic myself:
http://i.imgur.com/flpjX7b.jpg
http://i.imgur.com/oFdka0Y.jpg

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