Please take note when installing NForce Drivers
Make sure your Add/Remove Nvidia Driver has the entries below:
Use the 15.45 NForce Drivers I advised (Can be downloaded on Guru3d.com) DO NOT USE 15.37 NForce Drivers from Nvidia except for the AHCI Storage Driver from 15.37.
Note you get SMU Driver and PCI System Management Drivers, otherwise you get a Fatal Machine Check error occasionally in Windows 7 Event Log, you won't see any BSOD but the error log will be there .
In conclusion use the Storage Drivers from 15.37 and SMU and PCI System drivers from 15.45.
Please update the Storage Driver from 15.51 (from Guru3D) the driver from 15.37 causes occasional freezing issue.