|Right click on My Computer, then properties. The screen that appears should say what version of Windows you currently have. If it doesn't say Second Edition then you don't have it. The build number for SE is 4.10.2222A.|
If you have a CD that is marked as an upgrade that means the disk can be used to install Win98 on a computer that already has a previous qualifying version of Windows on it.
I believe the qualifying versions were/are Win3.11, Win95.
Does the disk say Win98SE on the label? It sounds like you are currently running Win98FE and the upgrade CD is for that version.
If that is the case then you will not be able to get to Win98SE by using that disk.
I can't advise you any further without knowing some details about your computer hardware or at least a brand and model. Even if you had Win98SE if the driver you downloaded is a generic USB driver it still may not work. In many cases those generic drivers do work, but not always.
If your computer was upgraded TO Win98FE it must be pretty old. May be time to bite the bullet and get something newer.