no admin on my pc

i no longer have admin, on my pc, it was accidently erased,now i (sharon) am under user with limted access, i cannot click on to it change or add. This is limiting to things i can do, and mostly not been able to down load anything,i do not no were my software is for my windows xp,as somebody had said i will have to reboot my pc and i will loose my pics ect. So i am at at total loss of what to do and would so appreicate any hep, thank you, SHARON,