Lag in game

Hey there guys first time for me in this forum. I have already installed the witcher and am not really enjoying it because i hate any form of lag in gaming im sure you guys know what i am talking about. I just played call of duty 4, and it ran beautifully on my com tts why i was surprised when the witcher lagged on my com. I have 7600 nvidia gts card, 1 gig ram, 2.13 ghz intel duo core processor. Especailly during the cut scenes there is a lot of lag in the game. What can i do to get rid of the lag? I ran it in 800 X 600 it was better but the cut scenes were very unclear… another doubt…. i dont even get the story progression the story seems very choppy.. like suddenly u arrive in the castle place and then u suddenly get transported to vizima i dun get whats going on will story become clearer later on?

If the cutscenes are a problem, disable "Depth of Field" (I believe that's the command - something like that, in any case) in the options. It helps tremendously with cutscenes. For the record, I've played the game with a weaker computer (single-core CPU with a lower clock), and it was fine enough.

The story might seem jumpy at times, but I think it's clear enough at the start: you show up at the fortress, fortress gets attacked, everyone spreads out to search for attackers, Geralt comes to Vizima (outskirts).

Have you gotten the latest patch installed? It made a world of difference in loading times. Cut off the grass details also, that might help.
As to the story, it will all work out. After having finished the game, I now feel the first two areas, the castle and the outskirts, are more to get you into the mood and feel of the game and the mind set it tries to create, with only a loose content of the main story added in at first. Sort of setting the stage so to say. If in doubt on what to do, just use the journal and do the quests. One of them will lead you to something new.