Ram confusion

I am putting an old computer together for the kids to surf the internet.
I just put in an old st340810a seagate hard drive and installed windows 98se
on it but i am confused about the ram. I have tried two separate sticks of
pc100 sdram sticks that are suppose to be 128mb but the computer tells me
that there is only 64. I realize that the on borad videto card takes 32mb but
where did the other32 go? The computer uses an old Pentinum processor. Could
this be the problem?
Any ideas ?
Thank you