By default, the Microsoft account (MSA) creation process only allows three new accounts to be created from a single IP address in a day to improve security for users. Because organizations or events often use proxy servers or NAT technology, requests from multiple computers are received from a single IP address, so the error occurs when the fourth person attempts to create an account.
Before customers, partners or field run events or attempt to engage in a Windows 8 deployment it is highly recommended to whitelist the relevant IP addresses (i.e. exclude from the blocking rule) so that users do not run into issues creating Microsoft accounts. This should be done within 30 days of the final day of an event, but not sooner.
The procedure for MSA IP whitelisting requests is facilitated via eform (https://support.live.com/eform.aspx?productKey=wlidipexc&ct=eformts&scrx=1) submission.