How can I stop my Wii from displaying error messages?

My Wii has been working nicely for a little under a year now, however after it took a trip in my schoolbag (it wasn't banged or anything, just moved) it refuses to do anything after I turn it on besides show the following message:

"An error has occured. Press the eject button and remove the disc, then turn the Wii console off and refer to the Wii Operations Manual for help troubleshooting."

The operations manual told me to unplug it for 5 minutes and try again, but it still displayed the same message. It went as far as the home screen, then the error message appeared.
Is there anyway to fix this or do I have to buy a new Wii?? :(