GUI won't boot after installing upstart

[Valtam]

Linux Lite is based on Ubuntu, that doesn't always translate to everything that you can do on Ubuntu, you can do on LL.  Especially when it comes to replacing an enter init system, you're playing with fire.
Back up what you need to with a Live DVD to a USB, then reinstall Linux Lite. If you really don't want to use systemd, pick an OS that fully supports alternative init systems.
For those that like to play, you could try this in a VM first - http://without-systemd.org/wiki/index.ph...ated_pages but there is no way even I would touch that stuff, there's no telling what the future impact on the system with regards to updates etc would have. Cheers