I bought The Witcher two days ago, and so far it has been a truly great experience. However, I seem to have stumbled upon a major game-breaking issue.

The game freezes a few lines into the very first conversation that Geralt has with Reverend - it always happens at the exactly same moment, when the witcher begins saying: "I'm a witcher, I could help you". What follows a little while after is a "Blue Screen of Death" reporting kernel_stack_inpage_error.
My web search did not yield much information on this specific topic, and it boggles me as to why it would always crash at that exact point. Besides one other random crash (while saving the game, it did not repeat again) I had no other issues during several hours of gameplay.

I'm playing on a notebook (Intel Core 2 Duo 2.50 GHz; 2046 RAM; GeForce 9500 GS) with Windows Vista 32bit. The system is original, all the latest updates.
I've tried manually increasing the amount of virtual memory that is being used (up to 3072 MB), but it doesn't seem to make any difference. I've run the game as administrator, tried lowering graphic resolution, running it under Windows XP mode, etc. All to no avail. Every time it does stop at the same moment in the conversation.

I have yet to try reinstalling the game (in hopes that maybe somehow one particular file responsible for this very conversation got corrupted), and I've heard that playing in windowed mode seems to help people with various Vista-related crashes. But in the meantime, I thought I would try and see if anyone here had a similar issue.

I don't have much advice to offer unfortunately, but I wonder if it's possible to try and skip that line of dialogue? Usually you can click to skip lines in dialogue and maybe if you try skipping it you can bypass the crash.

Using windowed mode has been known to fix random crashes in the game so it's worth a shot, but it sounds like you're experiencing a very specific crash so I don't know if it will help.

That doesn't sound like game issue at all.
Check Windows event viewer. Are there any particular errors around the crash time?

There should be an error code (info here) and possibly a listing pointing to where the problem is - for example :

KERNEL_STACK_INPAGE_ERROR

...

Tehnical information:

***STOP: 0x0000007A ( 0xC05CF288, 0xC0000185, 0xB9E51642, 0x6FADF860 )

*** ftdisk.sys - Address B9E51642 base at B9E47000, Datestamp 3b7d8419

Beginning dump of physical memory
...

I managed to bypass the issue by using a certain "workaround" - the workaround being my brother and his notebook dropping by. He has Windows 7 and a better hardware all around. So I installed the game/flash mod over there, moved my save(-s) and went through the problematic dialogue line without any problems. Then I brought the post-conversation save back to my machine. It all worked flawlessly - every other dialogue with Reverend caused no issues (to my great relief), and I'm now past Chapter I.

Not an ideal solution, but it was frustrating enough already having spent so many hours on this problem. I did keep the pre-conversation save just in case, to possibly experiment with at a later time (after all, I still had a few suggestions to check).
Thank you for your advices. And as for the specific questions/notes: I came up with the same idea, but it didn't do much good. There seems to be a slight delay whenever you are clicking through the lines, so each line of dialogue will eventually "fire" - even if it's just for a split second. And the very moment this particular line had its turn, everything came to a sudden halt. If not a game-related issue, then what do you suspect it could be? I suppose a corrupted file/drive sector might be a potential culprit.
There was nothing out of ordinary (i.e. events that haven't been happening for the past few weeks/months) reported in the Event Viewer, as far as I could tell. I made sure to update all my drivers when I encountered this issue, but it made no noticeable difference. Mhm, but as you can see - it's all vague at best. It's hard to determine the real source of the problem with any certainty.

HI :)

Did you patch your game after buying it, or was it already patched by you buying the Diamond (enhanced) version of the game? Patches can be found here:

http://www.strategyinformer.com/pc/patches/thewitcher/patch.html