Hi and Welcome!
Are you running Win98 or 98SE? If 98 (non-SE), then forget it.
What you need on a Win98SE system, is:
Fully functional USB 2.0 hi-speed interfaces. Unless an add-on card has been installed, these don’t exist on computers that were shipped with Win98SE.
Device driver for external USB storage. In former times, they were shipped with external units. As Win98 is considered dead, they saved the money for providing drivers. You may try these GENERIC drivers here: http://www.technical-assistance.co.uk/kb/usbmsd98.php
If all conditions are given, then you are done and can go ahead.