Windows 7 - Unexpected I/O error has occurred

Hey guys. I am afraid that I have screwed up my acer laptop, which had fallen to the ground(I was actually sleepwalking and I somehow knocked it down really hard).
Starting up the computer, I got:
0xc00000e9
Unexpected I/O errorhas occured.
Windows had encountered a problem communicating with a device connected to your computer.
This error can be caused by unplugging a removable stoarge device such as an external USB drive harddrive....bla bla bla

I am very much unacquainted with computers when it comes to solving problems like this. I'm afraid I screwed up my harddrive...
What is the cause of this?
And can you please explain to me how I can rectify this problem in different ways(as I know it may not necessarily be the harddrive I wrecked)?

I also have windows 7 Home

Hello yellowkataki. Welcome to the Forum.

That error is most often associated with a failed hard drive. But since you knocked the PC to the floor the possibility that the hard drive is simply disconnected is pretty good.

If you are handy, and have a set of small screwdrivers and such, then you could open the laptop up and check it for any loose or disconnected parts.

It is best to download the PDF copy of your laptop's Service Manual and read it before attempting this. There will be pictograms and they will give you the order that things must go in and out.

If you are not mechanically inclined then my best advice would be to take it to a repair shop, or if that is a funny idea in central Australia then you could ship it to an authorized repair center.

Most disappointingly, that error could also be caused by a cracked or broken motherboard, or an actual hard drive failure. Shock is a common cause of hard drive failure. So you've got to hope that something just got jarred loose.

Was your computer switched on when it was knocked over? If so there is a good chance that the head have crashed onto the surface of the hard disk and caused the error report.