Windows vista user account dissapeared help?

So I log onto my computer and it goes to the welcome screen and my account is gone and all it says is other user and I don't have another user and when I type something in the user name or password box a message pops up that says " the specified domain either does not exist or could not be contacted." and so I restart and press F8 and I tried clicking on repair your computer and that just brought me back to the welcome screen and then I tried safe mode and it started to load then crash same thing happend when I clicked all of the following safe mode with networking, safe mode with command prompt, please help me a person can only go so long without a computer all of my pictures were on there that I will never get back if I don't figure this out and it's Windows Vista thanks For your help!