There is no single smoking gun. CTDs have been caused by mod conflicts, video drivers, and lack of memory, as well as geniune Dawnguard bugs. My PC has 16GB of RAM (certified stable through testing) and dual high-end video cards, yet the game still crashes frequently... so I'm sure it's not a "lack of memory" or "bad memory" issue. I'm in the process of disabling each of my 30 mods and have found some candidates (Crimson Tide Blood is the most suspicious, from what I gather reading other threads), and have installed the latest AMD drivers that were released yesterday, but can't say at this time whether that will eliminate or even reduce the crashes.

im still stuck on the first quest ( Bloodstone Chalice, PC ) >.< yes i could use PC skip stage quests but i dont want to as it spoils it for me -.- its probably the first time i've felt REALLY let down by beth.

Honestly i waited so badly for this and im sad since the 90s and Arena i bought all TES titles , add ons ect. It was never bugfree , but what existing game is. But things started to realy get scary with Oblivion......and now Skyrim damn i would buy it without blinking normaly ...but all the stuff im reading im into 70% gutfeeling :better wait for a patch.
And that makes me sad again

I only found 2 bugs with Dawnguard so far. One is gamebreaking at the moment, but I can avoid it happening myself, the other one I can fix with a simple console command. So yeah, for me it's been good.

I've also got a gamebreaking bug on my Nord level 70 character, I can't read the Elder Scroll (Blood). I've already collected tree bark and there are moths following me, but I can't read the scroll. I tried to reload to a previous save but that didn't help. Just with all the other patches Bethesda breaks more than that they fix. On my level 52 Breton I've also experienced some bugs, I either fixed them with console commands or reloading to a previous save.

Terrible, simply terrible.

Seemed to work ok until Serana started following me and we left the crypt (early in the storyline) then, bam, CTD's every few minutes. Only mods I was using was beth own HD textures and the "unofficial" patch. Disabling the unofficial patch never helped. Stability never returned until I disabled Dawnguard completely. i7, Radeon 5850.

I had a hard time with complete freezes up until I actually started Dawnguard with both of my characters. After the quest was started it straightened back out. Took me a LOT of tries to actually get it going. Is it still a little buggy? Well, it IS Bethesda after all. But all in all I am really enjoying it now.

The game performed horribly before the 1.4/1.5 patches. By 1.6 everything was as smooth as butter. When 1.7 came out or Dawnguard, I'm not sure which is the culprit since I got both at the same time, I now get lower frame rates in places I had none before. Also the menus seem, from the main menu to even the inventory/magc menus, to operate at 20 to 30 fps.

Version 1.7 absolutley breaks the game.

Some people are having their saved games not loading anymore. Some are not. That could be due to mod data in the save game files not compatible with 1.7 or possible corruption from a catalyst in the 1.7 patch.

http://www.gamesas.com/topic/1400758-dawnguard-pc-version-bug-list/ of known 1.7/Dawnguard bugs here on the forum is terrifying. Game breaking bugs just got amplified by 100x with this patch. I just paid $19.99 for an expansion pack that not only doesn't work but it's related patch breaks other non-Dawnguard related things as well.

I'll be trying to figure out a way to restore the game back to version 1.6 when everything performed 99% perfect and the game breaking bugs were more isloated and controlled by community made mods. If anyone knows how to prevent Steam from installing 1.7 please let me know. I figured the only way to restore it back to 1.6 is to install from scratch again, then block the 1.7 update (somehow).

For reference here are my system specs:

• CPU: Intel i3-2120
  
• RAM: 4GB DDR3
  
• GPU: Geforce 550 Ti
  
• OS: Windows XP SP3

My mods:

• Official Space Core mod
  
• Dawnguard

Here's to hoping 1.8 will be magical like 1.4/1.5 was to us in the past. For right now, I just paid gamesas and Steam $19.99 to NOT play their game because it's broken. I'll be spending my time on NBA2K11 going in full rebuild mode. Maybe by the time I tank an 82 game regular season for lottery picks gamesas will have a working 1.8 patch that at the very least restores the game to the way it was in 1.6 when it was perfect for others and myself.

Since many of the problems are being caused by mods, I would ask Bethesda to release information on the Dawnguard expansion for the Creation Kit so modders know what is conflicting with Dawnguard. I realize that any issues I encounter with mods are my own responsibility, since I chose to install them, but... that said, I have three characters whose savegames are ruined because they contain remnants of mods that now cause Skyrim to horribly crash, and crash often.

The only way to play anything right now is to disable Dawnguard altogether and play vanilla Skyrim until the issues are addressed. I accept that, but I was looking forward so much to playing through this thing. (I got as far as the Soul Cairn without any problems, but once I entered it... crash-o-rama.)

The only bug I've been getting since Dawnguard is that the game constantly freezes and I have to use the task manager to close it. Sometimes it happens after only 3-5 minutes of playtime.

I've tried new save games, old save games, with mods and without, yet Dawnguard causes frequent crashes. The moment I disable it, gameplay is completely stable.

Since I installed Dawnguard, I've also upgraded my computer, only to find out that Dawnguard STILL CTDs on my new card...

As far as memory goes, 4 GB RAM should be more than enough, even if it adds up to threesomething in practice. (Total plus Kernel is just about three gigs. I'm not entirely sure where that other Gigabyte of RAM is supposed to be...) Not to mention, I have two gigs of video RAM...

I guess I should be lucky that I can still play Skyrim. It's just Dawnguard that causes issues. When I disable Dawnguard.esm the game is completely stable... (My first and only crashes for Skyrim have been with Dawnguard enabled. I actually never had an issue with them before the DLC)

Crashes, lots of em. Game dies every single time memory use goes above 1.3gb, which isnt near enough to saturate my 4gb total. Mods dont seem to be at fault for once, beefing up the vanilla game with some .ini setting and the official texture packs can do the same thing.

For now I can recommend anyone who randomly crashes outside whilst traveling a lot to turn off memory intensive mods, ini setting which load in more cells than normal and possibly reduce texture quality.

has beth said anything about patch fixes for dawnguard? any mods got some info?

Depends on how much mods do you use on SKyrim.

I only use Apachi′s Hair, daedric armor and the vampirelord revamp mods, and I′m fine and pleased with the game.

to resume: You don′t buy it> your loss

This really...I think most of the problems are with mods. Especially if it overhauls parts of the game or alters them in a way that it conflicts with DG. Take ASIS for example, before it's recent beta update, it caused big problems.
Otherwise, I'd say that DG PC isn't a horror story.

im using no mods and i cant get past the first or second quest.. a horror story enough for me

Two questions:
1. Have you used mods on this save before? A lot of mods use scripts that still run even if you disable the mod.
2. Are you referring to the Awakening quest (first dungeon-based quest) by any chance?
I was having problems with it too. CTDs whenever I entered the 3rd/4th chamber/corridor; and CTDs during the final fight (after triggering the lever). I only got passed it by saving them game before these two points. I was able to complete the quest this way.

1.nope raw save file never used a mod (XP = current version with mods, Win7 Raw Skyrim+DG, just to check if it was me lol
2.again nope the stupid chalice quest..

seriously i just wanna bloody play the game come on beth..

Horrible, don't waste your money.

I'm stuck with some major plot npc attacking everybody.

I haven't had any problems at all. (Some ctd's but they were mod related and now have straightened out) I was able to do Dawnguard from front to back. I haven't really done any side quests related to it though. I liked it, was it worth $20? Probably not.. but it adds some cool things that maybe some mods will utilize so maybe that will make it more worth the money.

I only have six Follower Mods installed in proper advised load order, the only time my game crashes to desktop is when my character try to find the Dimhollow Crypt on foot in the area Dawnstar for some strange reason, please fix these various annoying Dawnguard bugs and issues very quickly please Bethesda!

It is unplayable , ctds constantly in exterior so far I am still waiting for a patch or a refund perhaps .

Well for me I often times get stuck in an endless loop when I try to feed, I cannot enthrall the Moth Priest, when I try to feed on him he just talks to me...

CTD's and freezes...both in exterior and indoor locations. NO MODS. Had no problems until 7-10 days ago. Now, just grief.