I'm not to sure what this is or if it is normal, but I decided to post it.
While I was posting a topic I was typing and stuff and mispelled something. I was hitting back and then my finger slipped and hit something else with backspace. I tried to do it again, nothing happened. I took a screeny just in case, so, if anyone knows what happened or something, thanks.

You clicked an icon to open the Developer Tool built into Internet Explorer 8. Just close the window.

I.e. You hit F12. That does the same thing.