I am not an expert but after a lot of troublesome procedure I am finally able to get my system up and running.
I would recommand to read this post, which helped me a lot.http://forum.linuxmce.org/index.php?topic=8838.0
also, I would recommand few additional steps to avoid future troubles.
1. please set up initial set up (first time "sara" comes up) with VGA connection to your monitor. pick basic settings on first setup. Remember you can always change this settings later on once the first setup configured successfully. So pick basic gui, simple audio etc and add user name and room set up.
2. once you have everything working under basic with VGA settings try to run AV wizard again and now pick HDMI, UI3 this will also install latest nvidia driver for you automatically and should work just fine.
3. I installed latest alsa package before installing linuxmce.. gave me optical audio out with no trouble.
If you are going to use any tuner card. I would recommand hold them until everything runs fine.. and add your additional component one by one.
One key thing is ,, be ready to often reboot or reload your router after every single steps. i know it takes time but worth it.( I prefer reboot)
also,, if you are newbiee really,,, read wiki and more and more stuff will make sense to you.
there are some tutorials by a user name pandaman on youtube about linuxmce ,, what can I say,, he is my mentor !!!
I am loving it.
hope this helps..