At the risk of accidentally treating you like a brainless infant (Not my intention, I assure you.) I'm going to explain this step by step, assuming you know nothing. If you're much smarter than this, just ignore what you already know, and follow the instructions you don't.
You have an NVidia card, so you will be using the Nvidia control panel, which has been in existence since a few years ago.
1: Right click on your desktop, and click NVidia Control Panel. If you don't see that option, update your graphics card drivers and try again.
2: There should be three "tasks" to your left. Expand the "Display" task, and click on "Run display optimization wizard."
3: Follow the directions. Your display should now be perfectly calibrated.
4: If you want finer or more manual control over the calibration, click "adjust desktop color settings" under the "display" task.
5: If this is completely different from what you were thinking, and I just wasted this whole post, then please explain what it is you want to achieve again, only different.