The three most common reasons that you will not be able to access your account are:
1 - You have forgotten the password
Go to Password Assistance to request a new password.
2 - You can't remember your username
Contact Service Desk on tel. 77777
3 - Your CERN affiliation has expired, and therefore your accounts have been blocked.
Contact the Service Desk who will be able to direct you to the relevant services to reactivate your CERN affiliation and accounts.