I just upgraded my Macbook Pro (late 2008) to Yosemite today and after the instillation finished it asks me to log in (as it does whenever the computer restarts). However this time it does not accept my password to log in. Every time i try and log in the screen shakes and prevents me from logging in. I have not changed my password on my computer, ever. I have used the same password for years. I thought, maybe it could be asking for my apple ID password (which is different) but that does not work either. I checked to make sure caps lock was not on (it wasn't and I still had problems) then I put caps lock on to see if that would fix it (it didn't), then I tried every iteration of my password that I could think of, then I tried every other password I use just to see if there is some mix up somewhere. All of these did not work out at all. I still cannot log into my profile at all. Although I can still log in a a guest. I think that means the install itself worked, just not my password. I googled and did not find anyone else with this issue. Is there a way to fix this?