Before you can sign in to this Microsoft account and use it with Microsoft websites and services, you need a parent's permission. If your parent is available now, ask them to sign in to this PC.

but actually this is another email that I usually use to contact with my suppliers and clients. The reasons that has been blocked because I changed the year of birth. It's my fault and stupidity as I wanted to be easy to remember for my company that was established in 2005. So. I changed to be 1st March 2005. It means this account becomes kid's account. 

Please help. What can I do to use this account again as I have to contact my clients and suppliers. 

Thank you for your help. 

Best regards, 

Art