I've been using Skyrim via Steam for a few months without problems but this week it shuts down when you reach the black screen showing your character level and gameplay hints. I can choose a load point, go through options and settings, but as soon as I try to play the game itself it shuts down a few seconds into the level/hint loading screen.

The only change I've made recently is adding the high-res textures pack but the game was running fine with this add-on for nearly two weeks. I've attempted to load the game without the pack, tried the offline sync option which was recommended by some other users, running Steam and the separate loader with admin permissions, and a full reinstall, but the error still persists...