PC133 is backwards compatible, why do you need PC100? I have a few Kingston 256MB PC133 sticks left, as well as some 128mb PC100 sticks.
Yes I know that, but on some computers pc133 will just not work. Normally they are HP or Compaq computers that is picky. Also I think its the intel 440BX chipset is one that has problems as well with PC133. The very first thing I tried was PC133 infact I probably have 10 sticks of PC133 right now not being used that I did try to get it to work but it does not work.