Fails to load in Safe mode

Win98se MSI MB AMD 750mgb. System boots normally and runs ok but freezes running safe mode. Haaaangs at hour glass at desktop before “Safemode” splash screen. tried reinstalling over the top, Formatting and re ghosting the original ghost of 12 months ago from clean install but still no go.(was fault always there?)Have entered SF on a few occasions and removed nearly everthing in Device manager. Ran system file checker, Norton 2002, Ndd, scanreg /restore enabled me to get in once but then Failed to enter Safe mode again. Help please