open control panel, look for system configuration, expand menues, looking for keyboard property, see if it's right setting for your current keyboard. if it's not, delete those property, and refresh it, before you do this, (sure you can use mouse for further action) if your PC can't detect the keyboard, back to control panel, hardware detection wizards, (sorry I forgot actual name of it) system will search. and detect.
also check for your language, region setting.