Logon password how to delete or bypass

[envelope]

Hello, I joined today just so I could ask this question. I have read many other posts on the net regarding this problem for months now and have followed through with every suggestion made that I was technically equipped to do and so far, nothing has made a difference.
The first screen I come to when I start up is this, ' a white X in a red circle, then the words, 'Username or Password incorrect'. Below are the letters, OK. I click on OK and the next box gives the choice to Switch User, which then gives me two pictures to click on that are identical. They both come up with a white box to type in my password.
I have tried everything to be able to delete these requests for a password and go directly into my desktop but nothing works.
I've only had the Vista since last September when I downloaded it myself over Win7 with discs that I had ordered years ago with my computer.
I am the only one in the house that uses the computer and so there are no safety issues here that I need to worry about and I know it is not a big deal, but it would be so much more convenient if I didn't have to always log in each time.
Like I said, I've tried everything I've ever found online and so wonder if there is something else.
Is it possible that when the Updates became downloaded automatically that something was locked in that I can't get to and change?

I'm really not that computer saavy so I can't do anything really too technically involved. Could someone tell me if they think they might have any ideas or suggestions as to what I could do to solve this? I would really appreciate any and all help, Envelope