Yeah, by shutting it down you probably reset whatever error.
You're able to get into your BIOS when you are booting up - you hit whatever F-Key (it should say) to get into your BIOS. If you don't know anything about it, have a friend who knows show you, don't bother on your own. If you get into your BIOS, if you don't know what to do then just leave everything as it is. Otherwise, changing the wrong thing, or disabling something, youu could render your computer useless.
Um, for future reference, make SURE you do NOT plug in
anything into your computer -
Except for USB, this one is okay. If something should come
Unplugged you should properly shut down your computer and plug it in while the computer is off, then turn on your computer.
With USB, you can plug/unplug it while it's on or off. It's fine.

I hope you don't have any more problems, but I'm happy to help if you do. Take care.