'The user profile service service failed the logon....'

and then it continues on to say 'User profile cannot be loaded'

So when i logged onto my computer today as normal, the screen was black and im sure it had a little window open which said 'Loading personalised settings' and then after that, im sure i seen a window which said 'Windows 7 service pack 1 now available' and then when my desktop came on, the wallpaper had been changed to default, literally all my icons had disappeared, there was nothing in my pictures or downloads folder which is were i keep my downloaded movies and series, and Google chrome wasnt there and instead internet explorer was, kinda like my computer had been reset to factory default.

But some of my games was still on the desktop, and skype was there, and when i double clicked skype it started installing it. So i have restarted my computer a few times, shut it down and started it up again and same thing, and i looked at the most recent windows updates and the latest one had been installed on the 10th of October 2013 so that surely cant't be the problem? I should also mention that i checked the hard drive and it had the same memory like everything was still on it, 23gb left of 297gb, the same with my other hard drive, the memory was still the same. And now it isnt logging me into my profile at all, its saying what i mentioned at the very top,

''The user profile service service failed the logon. User profile cannot be loaded'

What is the problem here and how can it be fixed? If it can, thank you for any help or advice!

I only had one admin account which was my account, the one i can't get into, and im trying to change the other account (the one im using now) to an admin one, and whenever it comes up with the window for me to put in my password, you know since you have to be an admin to give that right, i put in the password, press enter and the window disappears and nothing happens, like a new window doesnt appear, it doesnt take me to a menu or anything, it just disappears, i also clicked enter to be sure but the same thing happens, just disappears and nothing happens