1. Check NumLock is switched OFF, then check if that has helped
  2. Hold CTRL and press Shift, then check if that has helped
  3. Hold ALT (or ALT GR) and press Shift, then check if that has helped
  4. Check your languages settings are set to the correct value. (For me that is UK English, and I got to them by pressing the Windows key and typing either ‘lang’ or ‘keyb’)