Gamma changes automatically

[Huboi]

So i have for a while had this pc and now i'm trying to change the gamma level by using windows colour calibration, but whenever i change the slider, the gamma level that comes out of my screen is the same. Tried to change it in nvidia's controlpanel but that wouldn't change anything either. Im using a sony kdl-26ex302 screen (i know dont tell me)

i've tried to change it on the tv istelf but i couldn't find a option ANYWHERE to make it be automatic, and the screenshots are just the same, meaing basically its on the computer itself. (since the screenshots are images before it was sent to the tv, and was not change from the outcome of the tv and bla bla bla..)

And my specs:

 

Processor Intel® Core i7-3770S CPU @ 3.10GHz

Video Card NVIDIA GeForce GTX 680

Memory 16 GB

Operating System Microsoft Windows 8 Professional Edition (build 9200), 64-bit

 

dunno if this was relevant or not but whatevss.

 

before:

 

after: