Non detection of hard disk in dell laptop while ...

Question

I hve purchased new dell laptop with dos.
When i m trying to install win xp Sp2 or Win 2003 Server ,it shows the error hard disk cannot b dected.
But i can install Win Vista easily.There is an ESIA Partition of 30 MB in my HDD which cannot b deleted ,it is fat 16 partition.
How can i install win XP SP 2 on my laptop ??
Plz Hlp me out, bcoz i could not keep vista in my pc as it is a triyal version and valid for 30 days only.