Login Problem

I have a Vista Home premium laptop I use occasionally. I used it a couple of weeks ago and ISTR it did some updates when I logged out. I turned it on yesterday and it will no longer accept my account password. In fact it only shows bullets for the first five of the password which is seven long. The password prompt appears so I am sure I am entering the right password. I do not have caps lock on either.

None of the safe modes work i.e they have the identical problem.

How do I fix this?