A Win 98/ME boot floppy will work to boot the PC, but if the disks are NTFS
you won't be able to see them, unless you get some special drivers for DOS.
A better bet is the XP recovery console run form the XP CDROM. It is a
DOS-like environment that can be used to fix a few things. However, it is a
very limited environment. For example, "COPY" works on a single file, but
not with woldcars, and "XCOPY" does not work at all. Be sure that you know
your administrator password!
Even better is to make a bootable CD via "PE builder", a free program that
takes some XP files, some freeware files, and produces an ISO-type file that
you then burn to CD. You will need a full-featured CD burner program like
Nero or Easy CD Cretaor. This CD will boot you into a windows-like
environment, with complete read/write access to the PC. It will also handle
external USB disks, if they are plugged-in before you boot via the CD.