If you know the email address you registered with and can still receive email at that address, go to the Lost Password Recovery Form and fill in that email address. You will be sent your user name and instructions for resetting your password. If you are sure of your email address but get "The email address you entered is not in our database" it means there is no MacRumors account with that email address. Either you used a different email address for your MacRumors account or you have us confused with another Mac-related forum site.
After you reset your password, you can use the Password page to change your password to one you can remember. You can change your account's email address there as well.
Remember to use a strong password so that nobody else can gain access to your account. A good password is many characters long, not a word from the dictionary, not your user name, and not a trivial pattern like 123456. Letters, digits, and special characters are all allowed.
If you have forgotten your password and either forgotten your registration email address or can no longer receive email at that email address, contact us for assistance. Tell us your forum user name, current email address, and any other information you remember about your MacRumors account so we can look up your account.
See Forum tip: keep your email address up to date