Hi,
On windows 98, you would need to install drivers to make the USB device work. In windows 2000 and up, it would automatically detect the device. But you have done that, so it can't be that.
So like Zero4Zero said, it could be a conflict.
Go to the control panel, and press the Hardware tab, then Device Manager. A conflict would probably mean the device listed there would have some kind of image, maybe a question mark.
Have you tried installing the drivers while detecting it? If not, try doing it this way.
Go to the Control panel, go to Add Hardware. Press next until it gives you more options. It should say something like 'Is the device plugged in?' so make sure it is plugged in, and press next. Then it might say it has found new hardware (unless this is only with win2k and xp)... then procede to say you have a disc to install it, and say to look for the cd, or floppy, or wherever you got the drivers from. It might then install it and everything will be fine.
If you have tried this. Are you sure it is not detecting it? Maybe it still needs setting up. Go to the Control Panel, and go to Printers. Check that it is there, and if not. You have your problem. Just say to install a new printer and then choose settings (USB for example) and the printer name. You might then be fine...
Hope all this helps...
*KaGe*