Boot from a floppy and at the A:\ prompt type format C:/Q, and confirm <Y> when it asks.
The /Q switch performs a quick format, when it completes and asks for a partition name type DISK1_PART1 and hit enter.
Then at the A:\ prompt type c:\ and hit enter, you will then be in the C:\ drive, type MD W98 and hit enter and then type CD W98.
You will then be in the W98 directory you created with the MD command, type COPY D:\WIN98 <if D:\ is your CD-ROM drive> to copy the Win98 setup files and CABS to your hard disk, then type setup.exe and complete the install.