You should not be able to log off the LiveCD SYSTEM user

Issue: If you choose "Log off SYSTEM..." in the LiveCD version of ReactOS 0.5 SVN, you will be logged off, but unable to log back in as the SYSTEM account does not exist and is used as the LiveCD to auto-login.

Resolution: Disable "Log off SYSTEM...." option in the start menu (and and the shutdown prompt, so "Log off SYSTEM" is not displayed or if the system is logged off, instead of showing the ReactOS logon prompt, show the "ReactOS LiveCD Welcome" screen (where it offers to Try the LiveCD or Install ReactOS).

Versions affected: 0.5.x SVN onwards.