Reformated computer lost pictures

hello, I am new here. I see a lot of people having the same kind of problems I have encountered. I have read a lot of questions, but I do not see where others reply. I must be doing something wrong. I child's computer recently contracted a virus. We were walked through to restore the whole system.
Upon doing so pictures that I thought were on my cameras memory card are not there and I lost them. Can someone please help me. I would really appreciate your expertise. Thank you.