Last night I was using my macbook fine as normal, this morning when I switch it on it boots up to the normal login screen asking for my username and password but when I go to type, the keyboard is non-reponsive. The tab key works, the space bar works, the return key works, the number keys work, but when I try to type my username using the letter keys, nothing. It's like the letters buttons aren't working but everything else is. No letters will type in the 'Name' section of the login screen, but every letter except B and F will type in the 'Password' section, yet I cannot copy-n-paste from one to the other to get around this. It's very strange but it means I cannot start up my laptop or access any of my files, which I need for work. I don't know why or how this happened, everything was fine when I shut down last night. Please advise on how I can fix this or how to get around starting the macbook without logging in - this is urgent. Thanks in advance.