Have you anything using a USB connection which already works on this computer?
Double check by looking in Control Panel > System > Device manager and the list of things among the hardware on your computer. If it shows near the bottom of the list USB Controller/s then you should be able to get things going.
If something is listed there, then it should be possible to feed it the right driver for the pen drive even if the OS is bare 98.
98 can become confused when offered large figures like RAM over 512mb and HDs with over about 2Gb!