It sounds like the hand-wheel wasn't put on correctly.
It's a pretty easy fix:
- Take out the screw from the silver inner wheel which you would usually loosen to wind a bobbin.
- There should be a washer which sits in the larger hand-wheel.
- Remove the washer and turn it clockwise until it fits into the wheel again.
- Replace the silver inner wheel and screw.
This should work. If not, try again. It's a weird assembly that seems to work when the inner washer is placed correctly. With a little trial and error, you should be able to get it working correctly.
Good luck!