I assume that you are having trouble logging into forums, and that your laptop is working fine, AND that you are on another computer now, since you appear to be logged in.
Without knowing what operating system or browser you are using on the laptop, it is hard to be specific, but all browsers have 'options' or 'preferences' where these things can be adjusted. These are accessed from the menu bar. You will have to check each dropdown to find where yours is.
As for the password, most sites have a password recovery mechanism at or near the login, and it is usually presented when you fail to get in.