My motherboard states that it is compatible with either PC100 or PC133, and by default, was shipped set at PC100. The booklet states that if the RAM is PC100/133 compatible, then the setting in the BIOS can be manually changed from 100 to 133. The RAM I have states the same thing, it is compatible at either PC100 or PC133. The only place I have found a value of 100 in the BIOS is at the "CPU Overclocking". I have not worked with overclocking in the past, but, is this the setting in question? THANKS.