If for any reason you cannot login to the Herschel Helpdesk and re-setting your password is not possible, or does not work, you can raise a ticket in the Cosmos system, which supports the Herschel Helpdesk infrastructure, without logging in.

Go to https://support.cosmos.esa.int/cosmos/ and describe your issue in as much detail as possible, including the Operating System and browser that you are using. Cosmos will help you to resolve your login issues.