The best thing to do is to reformat and start again. To do this you will need to erase 98 and start again. Problem will be that you first need to be able to boot up your machine. Make sure you have a bootable floppy, with CD drivers or create one from your existing installation; alternatively, you may find that your PC can boot directly from CD. You need to check your chosen option works before progressing.
For floppy, use the floppy to boot up the computer then insert your CD and make sure you can see it. Now type in the command
and follow the instructions on screen. When advised that this is complete type in the command
x:\setup, where x: is the drive letter of your CD
and let the system install Windows.
If your PC will allow a CD boot, then boot from CD, format c:\ as above then install.