Hi,

there should not be any problems if you change the username of the global administrator, because the global administrator role is just like any other role, with the exception of the Is global administrator value enabled. So it is not a problem to rename the global administrator, create new user as a global administrator and then you can for example delete the default global admin account.

Best Regards,
Roman Konicek

Hi,

this may not be an answer to your question but I just wanted to point out that there is a feature called Invalid logon attampts. Works pretty well if you wanna avoid brute force attacks - you can say how many times someone should try to log in until they're locked out.

Here's the documentation: http://devnet.kentico.com/docs/devguide/index.html?invalid_logon_attempts.htm