W520 and calibration

[kuja01]

Hello everyone This is my first topic so nice to meet you all!
I would like to ask you for some help with my screen calibration.

I have a W520 and I spent a lot of time for the screen calibration, I'm actually using the integrated calibration device with the x-rite software but I'm not that happy.
The screen gets too blue or too red, I could not find a way to get a decent calibration and I can't actually spend additional money for an external calibration device
I also changed many options in the color management panel (I believe I also changed the system defaults and I can't remember the old ones lol can you help me with this too? my old notebook and the notebooks of almost all my friends have sRGB IEC61966-2.1 as system default, should I do the same for my W520?)
I don't know what to to do improve the calibration, do you have any suggestion?
How can I improve the calibration? I'm not looking for a perfect calibration but I would like to have something decent, any advice?
Thank you very much!

ps. I did several researches, read many topics but without usefull results