SureAI

I went into a cave on a river near the start of the game just after killing a bear, then I crashes to desktop. Now whenever I try to load a save or start a new game, the 'Skyrim' window stops responding after a few seconds. I've tried reinstalling the game and using old saves, but it didn't help. I've read it has something to do with SKSE, but haven't gotten further then that.

Both restarting your PC or deleting your autosaves may help with your problem - basically Skyrim every now and then tends to load errors (CTDs) into the cache, which is why you have to restart the PC to make it empty again.
Reinstalling Enderal or even Skyrim won't work as the cache never gets emptied while doing so.