Any motherboard that can use a 4gb memory module is far too new to have native Windows 98 drivers for any of its components. Windows 98 is best suited for older systems with 512mb of memory or less (lines have to be added to its system.ini file to limit the amount of usable memory to 512mb when more than that is physically present).
Windows 98 can be run in a virtual environment on today's hardware. VMWare and VirtualPC can run Windows 98 as a "virtual machine" (in emulation). VirtualPC has a few free versions available, and I believe there is a free version of VMWare, too (a "light" version).
Best of luck
. . . Gary