Can't login to macbook - keys not working


Hi there,

I am having trouble logging in to my older macbook. I get to the login screen, but am unable to type my password in - every time I try, I get that "can't type" sound. However, the function keys, and caps lock etc seem to work. It's just the letters and numbers that don't.

I've read around on the internet a bit and it seems other people have the same problem when "mouse keys" is enabled. There are guides about how to turn off mouse keys, but I can't access system preferences because I can't login. I'm not able to access these via the Mac disk either, because my CD Drive is broken.

Does anyone have any ideas about what I could do? Any help would be appreciated.