Do you have your installation disk, or are the installation files in your machine? The files in question are in the Net9.cab file in win98, and need to go into Windows/System folder. You can right click on the .cab file and choose Open or View, whatever is on the top of the menu, and it will open a folder view of the contents of the cabinet. Right click on the file you want and choose Extract, when you click extract a dialog box will come up, just direct the extraction tool to the system folder. You could also use System File Checker, but this will be simpler. You can also unzip each file to the folder, if your unzip utility overrides the extraction tool.
Hope that helps.