Boot problem. my notebook won't start with an xp os... need to fix it but won't boot thru an

Question

my notebook won't start with an xp os... need to fix it but won't boot thru an external cd drive (there's no internal drive by the way).... can anyone suggest what to do? i've tried F2, F8 and F10 and selected boot source but still won't work.... please help me, i need this for my studies...thank you