formatted hard disk as FAT32

After trying to format a USB thumbdrive, I got this error message when trying to boot: "NTLDR is missing". With a live Linux CD, I learned that I had formatted my entire hard disk to a single FAT32 partition.

Previously, the disk had an empty space at the beginning where a small hidden Dell utility partition used to be, and the rest was an NTFS partition.

Is there anything I can do to fix this? All the data is still there, but I don't know how to access it. My only tools are a Kubuntu 6.06 CD and a borrowed laptop with dialup internet access running Windows XP.

Its a shame your laptop most likely does not have a floppy disk drive.  You could make a DOS start up disk and then you could run fdisk after booting to DOS from the floppy. If you can get access to a PC which has a floppy this is the easiest way to go.
Insert floppy, select format, create MS DOS start up disk.