your hard disk is empty, or at least it does not have an operating system on it.
you should have a Windows 98 boot floppy disk
put that in the floppy drive and reboot.
you will boot to Dos then you should put your operating sytem cd in the drive and type d:\setup
or similar and installation should start.
If you are saying that the hd is a second one, you will need to enter your bios to tell the computer which hd to boot from.