I need to create a idiot proof overlay for my parents to use on their PC. It should look similar to the Steam Big Screen interface, but something like the Win. 8 Metro Interface would also be fine (as long as I can decide what programs showing up). I found this: http://mosaicproject.codeplex.com/releases/view/72544 but it´s not very nice to use. Any suggestions would be highly appreciated.
For what programs/usage?
I'd look into building a tailored Arch linux machine and use a custom launcher. Use Openbox and remove the right-click menu.
They mainly want to watch shows from the internet on their system, but also want to look at pictures/movies from a SD-card from their camera. Also they like playing Karaoke a lot I´ve just checked it, the program is also available on Linux. The problem is, that my experience on Linux is limited. So a Windows solution would be preferred.