Set your BIOS to start from floppy first.
Insert that bootable (win98)floppy and start the PC up (select: with CD-Rom support).
You may have to do an FDISK first. Program is on that boot-floppy. Delete whatever partitions are on the HD (if any). Then create partition, using the whole hard-disk. Set that partition "Active". Quit FDISK.
Reboot with the floppy still in, then format as above.
Then after the formatting, insert the CD as described above.