Hi. Are you running Windows x64 bit? If so you've simply clicked the wrong download button on the Nvidia site and downloaded the 32 bit driver by mistake.
You need to delete that and download the x64 driver.
Hope it's that simple
System Manufacturer/Model Number The Monolith. 3.1 OS Windows 7 Home Premium 64 bit CPU i7 2700K@4.5GHz Motherboard Gigabyte Z77-D3H Memory 2x4GB Corsair Vegeance DDR3 Graphics Card XFX GTX 260 Black Edition Sound Card none-through large stereo hi fi Monitor(s) Displays Croosover 27MDP LED IPS Dell 2408 WFP Screen Resolution 2560x1440 1920x1200
Keyboard Enermax Aurora Mouse Logitech Ballmouse PSU Corsair AX 850 Watt Case Cooler Master ACTS 840 Cooling Be Quiet! Dark Rock Pro Hard Drives 1x Samsung 840Pro 128GB SSD
1x Samsung Spinpoint F1 1TB Internet Speed 20MBPS
System Manufacturer/Model Number self build OS win 7 ultimate CPU amd phenom x4 9600 Motherboard asus m2n32-sli deluxe Memory corsair twinxs 2x2gb Graphics Card 2x nvidia 1gb 8500gt Sound Card onboard Monitor(s) Displays 19" lg ring tft
PSU oryxx tornado 750w Case thermaltake xaser lll Cooling artic freezer64 pro + 7 case fans Hard Drives maxtor sata 500gb
maxtor sata 320gb
fujitsu sata200gb