Help with Call of Duty 4 Vista

[Reisooh]

I've tryed playing the demo for Call of Duty 4 and the lag is unbearable. I tryed playing at full settings which lagged terribly, then i lowered everthing to the lowest resolution and setting (Lowest Textures, No AA). The game looked terrible then and it still lagged (same amount of lag). Something doesnt seem right. (FYI It's a singleplayer demo). I play Call of Duty 2 (online and offline) and it works flawlessly.

My System:
Manufacturer: Me
Processor: AMD Athlon(tm) 64 Processor 4000+, ~2.4GHz (Not Overclocked)
Motherboard: MSI K8N Neo4 Platinum
Memory: 2048MB RAM (Not Overclocked)
Hard Drive: 2x250gb raid 0 = 500gb + 160gb storage
Video Card: XFX NVidia GeForce 7800GT Factory Overclocked
Monitor: SyncMaster 225BW (Connected DVI)
Sound Card: Creative Soundblaster X-Fi XtremeGamer
Speakers/Headphones: Monsoon Speakers / Razer Barracuda HP-1 5.1 channel Surround Sound Headset
Keyboard: Logitech G15
Mouse: Razer Copperhead Tempest Blue
Operating System: Windows Vista? Ultimate


Please help me with this. Im getting the game tomorrow or tuesday, not sure yet, i really want to play it.

 

[Reisooh]

i just installed it on a much lesser computer (hardware-wise) but it runs xp. Game is amazing looking, good settings, perfectly smooth...


i think ill make this one a dual boot... anyone think that's a good idea?