Incorrect password

Hello my problem is I set up a password on my laptop and typed it twice, wrote it down and selected a prompt to help me if I forgot this password. I then logged out, now when I open my laptop I get the icon with my name under it but when I put in the password it tells me it is not correct, the prompt question to help you remember your password is there but the password I enter will not work, I can only think that I mis-typed or hit another key when entering my password.

I have tried using capital letters etc. and it will not allow access. My problem is I cannot open the computer at all to even set up another user. Would you please tell me how to get into the computer to reset my password. My laptop is an Acer Aspire 5332.
Thanks:embarased
Kath