Go here to sign in and edit your profile.
You do not need an account to open or download any simulations. You will need an account to download teacher-submitted activities or watch teacher primer videos. Go here to register for a free account.
You can resend the email confirmation here.
Sometimes, the confirmation will be marked as "spam" or be filtered by your email server. If you do not receive the second confirmation, try whitelisting "phethelp@colorado.edu" and resending the confirmation above.