Win98 loads & runs extremely slow

Question

I installed Windows 98 onto a brand new system, and it takes it between 5-10 minutes from when I hit the power button, to where it's finally ready for use. It also freezes often for approx. the same amount of time whiile installing or running programs. It will run perfectly when I load it in safe mode & when I put Win95 on it. It's a Pentium III 500mhz, A-Trend ATC-6240 motherboard, and I have tried PC100 RAM from 64MB to 512MB. Anyone know how I can get Win98 to work?Thanks