How to get computer going again?

my granddaughter went to system restore to get it on an earlier date and the way she is explaining is that she lost some things .not sure what.she is only 13 and not too computer literate.me either.her parents are busy.way busy to help.i;m in ga.and she's in fl.she needs it for homework and of course talking to her friends on facebook.can anyone help with this.hopefully you understand .thanks