Thank you "fatboys25"

Installation Notes:

This application package replaces all previous versions of the NVIDIA System Utility or NVIDIA nTune. Earlier versions of the application should be uninstalled and the system rebooted prior to installation of this package.
Support for the advanced features of the NVIDIA nTune requires vendor specific setup files that are not included with this package. Please contact your motherboard or system vendor for the correct files to enable this functionality.

Overview:

NVIDIA® nTune is the ultimate utility for accessing, monitoring, and adjusting your system components, including temperature and voltages with clear, user-friendly control panels. Overclock your system for highest performance or underclock it for near silent operation. All changes are performed within the Microsoft® Windows® interface – enabling full functionality without the need to make changes in the BIOS and reboot your system.

Supported OSes:
Windows XP (32-bit),
Windows XP x64 Edition
Windows Vista (32-bit)
Windows Vista x64 Edition

Version: 5.05.38.00
Release Date: April 26, 2007

U.S. English
File Size: 36.3 MB

International
File Size: 36.3 MB
Users without English US operating systems must download and install the International Driver available on our International Sites listed below:

English UK
France
Germany
India
Italy
Poland
Russia
Spain

You must accept the end-user licence agreement in the Nvidia control panel to use the performance section.

does it support C51 ??

MCP51/61 Should be fine to get ALL features.

Supported OSes:
Windows XP (32-bit),
Windows XP x64 Edition
Windows Vista (32-bit)
Windows Vista x64 Edition

Version: 5.05.47.00
Release Date: July 12, 2007
Overview:

NVIDIA® nTune is the ultimate utility for accessing, monitoring, and adjusting your system components, including temperature and voltages with clear, user-friendly control panels. Overclock your system for highest performance or underclock it for near silent operation. All changes are performed within the Microsoft® Windows® interface – enabling full functionality without the need to make changes in the BIOS and reboot your system.

Installation Notes:

This application package replaces all previous versions of the NVIDIA System Utility or NVIDIA nTune. Earlier versions of the application should be uninstalled and the system rebooted prior to installation of this package.
Support for the advanced features of the NVIDIA nTune requires vendor specific setup files that are not included with this package. Please contact your motherboard or system vendor for the correct files to enable this functionality.
Release Notes:

This is a complete, updated release of the NVIDIA nTune. You are not required to install a previous version of this application before installing the latest version.
nTune 5.05 adds support for GPU temperature monitoring and overclocking on all motherboards.
On nForce motherboards where specific BIOS support is not available, only basic functionality will be available.
Products support for advanced motherboard monitoring features:
nForce 220, nForce 220D, nForce 415 and nForce 420D
nForce2 and nForce2 400
nForce2 Ultra and nForce2 Ultra 400
nForce2 400R and nForce2 Ultra 400Gb
nForce3 150 and nForce3 PRO 150
nForce3 250, nForce3 250Gb and nForce3 PRO 250
nForce4 Pro 2200, nForce4 Ultra, and nForce4 SLI
nForce 590 SLI, nForce 570 SLI, nForce 570 Ultra, nForce 550
nForce 680a SLI, nForce 680i SLI/680i SLI LT, nForce 650i SLI/650i Ultra
Supported operating systems for this release:
Windows XP (32-bit)
Windows XP x64 Edition
Windows Vista (32-bit)
Windows Vista x64 Edition
Best when run at 1024x768 16-bit color

Version: 5.05.47.00
Release Date: July 12, 2007