No Signal Issue

Hello, I've come here for help on a problem that I'm having trouble solving. I'm not completely sure how to fix it because I'm not that well experienced with computer tech other than the basics and a bit more, not much.

This being said, I present you with my problem.

About a week ago I was messing around with my Win 8 desktop trying to connect it to my HDTV via HDMI port. So I go to the Windows Charms, I believe it's called, and selected "Devices". Under devices was an option for "Second Screen", or something along those lines. I clicked it and my screen went black. I really wasn't that concerned, so I just tried a variety of keys to exit this mode. Esc key, Ctrl Alt Delete, etc. but nothing helped.

I've tried turning it off and back on, unplugging and replugging, trying different TVs etc. Nothing worked.

What's strange is if I use the keyboard shortcut for Sleep Mode it actually puts it to sleep. Which makes me wonder if the computer is still intact but the screen is not.

Also when I boot it up it shows "No signal" and goes blank.

Sorry if this is the wrong thread for this problem. Any help is appreciated.

Thank you very much

You should be able to go into the devices location again and after choosing
Second Screen again, select Duplicate to return to normal mode.

Thanks, but I really can't see what I'm doing due to the screen being blank.

It's really frustrating to know such a simple way to fix a problem, but you can't see what you're doing.

Thanks again for the reply.