If you have the full version of 98SE it will do an upgrade, replacing older files with new ones.
Here's a trick most people don't know about: The OEM version of 98SE can also be used as an update, simply by deleting the win.com file from the original installation. That's the file 98SE OEM looks at to see if you're trying to perform a disallowed upgrade!
<font color=blue>Only a place as big as the internet could be home to a hero as big as Crashman!</font color=blue>
<font color=red>Only a place as big as the internet could be home to an ego as large as Crashman's!</font color=red>