1. Navigate to Settings > Change PC settings > Accounts > Other accounts. You can refer to Create New User Account in Windows 8 for screenshots steps – follow till steps number 3.
2. Click on Add a child’s account.
3. You can choose to add using the Microsoft account or Local account. The sign up process will be the same as in step 5 and 7 in Create New User Account in Windows 8
4. Your children’s account is now added.