Account losted

Question

i hav run a command net user administrator /active:nothis disables my account on my laptop it is the only account on that laptopnow there is no account on my laptop it become useless alt+ctrl+del is of no use it say acces deniedeven the safe mode doesnt help me i'm using window xp & acer aspire4720z laptop in safe mode a guest account aapears but it doesnt help me