IT MAY ALREADY BE ON YOUR PC AND YOU DO NOT KNOW IT.
You will have to turn on see hidden files and folders and also see system files in folder options. then look for
\\windows\options\cabs folder, the cabs are the cabinet files in the win98 folder on the cd. if you do have this folder all you have to do is open the cabs folder then click on setup or use a boot disk and navigate to this folder and type in enter then return, it will start the install process, you can either reinstall windows on top of itself or coppy to a newly formatted HD ...You will need a cd key so google aprogram called magic jellybean, it is a key finder and will find your cdkey for you. If you are installing windows on top of itself when windows asks where to install windows, select the windows directory \\windows what that will do is replace all your syatem files and leave all your data, unless something is wrong with your HD.