How do you reformat a hp elitebook?

so my hp elitebook 2730p won't boot up and it says missing windows/system32/config/system. if i reformat my computer, will this go away because my notebook can't even boot up. it will start loadin normally and then it gives me the missing windows/system32... error. i have nothin important on my notebook so i dont mind losin anything. can this be done and if so how. this is a school notebook so if i can reformat it, will i need a the admin pass. i rlly just want to fix my notebook asap but if i hav no choie, ill jus take it to radioshack or bac to my school.