I use Visual Studio 2012 Ultimate and Visual Studio 2010 Ultimate, I never came across any problem like yours.
I am not jumping to any conclusions just yet but I would think that the installation procedure had few problems so it could not download few files therefore the visual studio crashes.
I highly recommend you re-install the VS2012 Express. I also suggest you also ask this question on MSDN they normally tend to have a lot of good members experienced in using VS2012 and other Visual Studio products.
If it still fails re-format\re-install your OS then try install it then.
But it would also be worthwhile installing all available updates (if you haven't already done so.) As soon as I've installed a new Microsoft app, I run Windows Update to pick up all available updates, before using the app.