Can pictures still be found after re-booting computer system?

Hello all I am not a computer expert so I thought I would give it a shot and ask on here.my computer was rather slow my husband took it upon himself to reboot my system without my knoledge and I lost memorable pictures almost 3 years worth, is there any way to get them back or are they gone for good ? He had to insert 2 disc to reboot my system so the computer is as if it were brand new but I am so sad because I was going to make a scrap book for each of my daughter now I have only baby pictures and from 1-2 years of age, and since I only have pictures of this year which she is turning 6 in may I am so bummed :( any help would be greatly appreciated :) Please tell me these pictures aren't lost for good is there a back door in the system somewhere. Thanks for your time