I wanted to install Linux mint but accidentaly deleted my windows partition will all my data, can I recover it ?

Hello guys,

I Just did something terrible. I was following a tutorial on how to install linux mint 18 (debian edition) on youtube (https://youtu.be/oSdchGgZrMM?t=19m17s). And I have done the exact thing he have done in the video (at 19:30). I though this will give me the possibility to change the partition (and not to delete all prexisting partition). After doing this 2 second later I got only one partition. I said I hope I didn't deleted my windows partition but It was the case. I shut down my computer and restarted it without the usb but there was nothing to be seen. All my data erased.

But I have read somewhere that the HDD disk is not "really totaly deleted" when we delete it's only really deleted when we add something onto it. It's that true ? Can I recover my windows system with the data (or at least the data) ? If yes how can I proceed ? Do I need a special hardware ?

Otherwise I'm in a bad situation.