Device Mgr conflict
 

My Gateway P-II-Win 98SE, I have a Yellow Splat in Device Mgr, (System board
extension for PnP BIOS).
In Sys Properties/Properties a note say there is a resource conflict, Code
15, but the troubleshooter says no conflict exists. Remove/reboot PnP
doesn't help. Safe Mode there is no conflict because no drivers are loaded.
Reformat and reinstalling Windows doesn't help me. I strongly suspect modem
or video driver, but am not sure
How can I troubleshoot and solve this problem in the smartest manner. Thanks