What's wrong with my RAM?

[tu8lu]

I have 128 MB PC100 RAM. Only 33% is free when I use ISP with adv bar plux 3 or 4 more IE or netscape windows. Today I added another 128 MB PC100 RAM, but it is still only about 33% free when I opened the same windows as before. Today after I install linux on my computer, I noticed in the linux login window, it is claimed that the memory of my computer is only 56 MB. I'm totally confused. I built up this computer by myself. I used any default values for MB (CUSL2). Do I need to change something such as bios? Thanks.

 

[tu8lu]

just bumping. Need helps. Thanks.