chkdsk not valid drive c:

i have windows xp. when i turn on the PC, i have the message “press F1 for Boot or F2 for setup”
i ran system console recovery from “a:” and also from “d:” and type chkdsk with all parameters, /r , /p and drive only,
and display “the specified drive is not valid, or there is no disk in drive”
i type map and display

a: floppy
d: cd-rom

and the hard disk ????
i don?t know if fixboot, fixbmr can erase my files.

i want to recover some family photos.

thanks a lot.