You need a bootable floppy disk that contains the programs FDisk and
Format. Since you have Win98, that is what I would start with.

Download a "Windows Startup Disk" for Win98. You can obtain a Windows
Startup Disk at:

http://www.bootdisk.com/

Put the floppy in drive A: and turn on the computer. You should get a
DOS prompt. Run the FDisk program. (You should have a choice of FAT16
or FAT32.)

Restart the system with the floppy still in drive A: and run Format,
using the command:
    format c: /s

This will format drive C: and put the Windows system files on it.

Restart the system, this time with no floppy disk in drive A:. The
system should boot from drive C:.

Create a folder named Windows in drive C: and put a file in it named
Win.com. It makes absolutely no difference what is actually in this
file. You are creating Win.com because the Win98 upgrade CD will look
for a Win.com to verify that a version of Windows is already on the
harddisk. (Inane test.)

I'm unsure whether you will be able to access the CD-ROM at this
point. Put the Win98 CD into the CD drive and see if you can see it.
For example, try to change to drive D:. If you can see the Windows CD,
then run the file named setup.exe on the CD.

If you cannot see the CD, then you will have to add CD-ROM capability.
Here is how to add your CD-ROM driver to the boot disk. The boot disk
might be drive C: or it might be a Windows Startup Disk that you can
insert into drive A:.

The CD-ROM driver will normally have a name with the letters CD in it
and it will have the extension .SYS. One way to get a CD-ROM driver is
to run the installation program that came with the CD-ROM. Also, you
can usually get a driver from the web site of the company that made
the CD-ROM. Or you can search your C: drive for *CD*.SYS.

Using Notepad or any word processor, make a text file, name it
CONFIG.SYS and add it to the boot disk.  This file should look like
this, but with the name of your CD-ROM driver in place of
CDDRIVER.SYS:
DEVICE=CDDRIVER.SYS /D:MSCD000
DEVICE=HIMEM.SYS

Add a copy of MSCDEX.EXE to the boot disk. You can get MSCDEX from the
folder C:\Windows/Command.

Using Notepad or any word processor, make a text file, name it
AUTOEXEC.BAT and add it to the bootdisk.  It should look like this:
MSCDEX.EXE /D:MSCD000

Bill Starbuck (MVP)