I'm running Skyrim in Borderless Windowed Mode, which has never given me problems, I'm also using mods that have never given me problems. Yet now, I suddenly cannot progress past a certain point during the Night Terrors quest (the Daedric quest in Dawnstar, I think that's its name).

After taking the potion and going into the dream state, then releasing the miasma, I'm brought back into the present, after which I can take the soul gem. It's at that point that the game crashes every time, regardless of whether I have mods active or not, and I have no idea why. As I said, I've never had this issue before, could it be patch 1.8 and I'm only noticing it now as I'm trying to do a fresh playthrough ready for Dragonborn?

I have nearly every quest in the game done (I'm ignoring radiant quests and hand in x vegetable etc quests as they're repeatable and don't really count as far as I'm concerned) so i don't want to have to start again, and I need to do this quest so I can become the thane of Dawnstar. I also don't have Hearthfire or Dawnguard running, as I don't want vampire attacks happening until I'm completely done with Vanilla Skyrim (I hate it when questgivers die because they're to stupid to run away).

I've only just started playing the game for the first time and soon after leaving the starter caves. BANG! CtD no error message.

Skyrim crashes if you try to save the game after drinking the torpor.

Save before you drink the torpor, finish the quest and exit the temple before saving.

Alternatively you can use the console command listed in the bug section http://www.uesp.net/wiki/Skyrim:Waking_Nightmare#Bugs

Hmmm, I quicksave often because of random CTDs for literally no reason (as in, it will crash randomly, I'll restart the game back up, and this time it won't crash at the point it crashed previously, despite nothing being different), so I thought it was bad timing on my part, I will try again and not quicksave, and reply saying whether or not it crashed again.

Yep, didn't save and it worked perfectly this time. Would really like to know what causes the random CTDs and how to prevent it though, cos it's really annoying.