When I hit the @ symbol the " symbol comes up, how can I change this back to work properly?

I suspect that the keymap has become corrupted for that key.

There used to be a keymap utility available from Microsoft (Kernel Toys), but I can't find that any more. On the other hand, I think it only let you map ctrl, alt, shift and those types of keys.

I'll suggest that you Google "Keyboard Remap" and possibly find a replacement one out there.