Hello Kim Pham,
A couple things that i would need to know are:
1. What is your Username?
2. Do you have mulitple accounts?
3. Are you able to Login into the adCenter User Interface via web browser?
4. Have you tried resetting your password?
By answering these questions i will be able to give an accurate answer of what the issue my be. If you cannot reply to the post please contact support and any customer support agent will be able to assist you.
United States:
Telephone: (800) 518-5689 6:00am-18:00pm PST seven days a week
Easy Assist Remote Desktop Assistance: (866) 783-1045
Email: https://support.adcenter.msn.com/eform.aspx?productKey=adcenterss&ct=eformts
United Kingdom:
Telephone: 0800 633 5915 08:00 – 18:00 (UK) Monday – Sunday
Email: https://support.adcenter.msn.com/eform.aspx?productKey=adcenterss&ct=eformts
Canada Support:
Telephone: (800) 985-4671 6:00am-18:00pm PST seven days a week
Email: https://support.adcenter.msn.com/eform.aspx?productKey=adcenterss&ct=eformts
Singapore Support:
Telephone: (800) 518-5689 9:00 am – 11:00 am SST Monday through Friday
Email: https://support.adcenter.msn.com/eform.aspx?productKey=adcenterss&ct=eformts