Z-Tweaked drivers are a modified version of nvidia's forceware graphics card drivers which are tweaked for the purpose of improved performance. Whilst the standard forceware drivers are set for a balance of performance and image quality, the Z-Tweaked drivers try to squeeze more fps from your gfx card. These drivers are aimed purely at gamers who want higher fps from their games.
Note: this driver does not work with SLI.
Tweaked v158.19 for XP32:
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