Here's what I'd do, others may disagree but I've had good results installing the following, but not on your board.
1. Via 4-in-1 drivers - install all for Win98 (except IDE and AGP on your board) - install all for Win2k(except for AGP on your board.) Others have maintained that the IDE driver is not needed for Win2k on your board. I'd try both ways.
2. AMD Miniport driver - install on both OS's
3. USB Patch (Win98 SE) - Win98 only.