Why won't my Dell Inspiron 8100 accept 1GB of RAM

[joelatkinson]

Please forgive me if I'm posting this in the wrong location I am new to the site and new to working on computers.
I have a Dell Inspiron 8100 with a 1GHZ Pentium 3 processor and I'm running Windows XP Professional with a 20GB hard drive. It has an ethernt 10/100 card, a firewire port (IEEE1394), two USB 1.0 ports, a CD R/RW drive, and two ports for wireless cards. The computer works great but it runs slow I beleive because of running Windows XP. I've been looking into maxing out the RAM on my laptop and have come to the conclusion that the max RAM allowable is 512MB of 144-Pin SO-DIMM PC133, installed as two sticks of 256MB. My question is why can't I install 1GB of RAM installed as two sticks of 512MB? What is the issue or issues that prevent this from being possible? I ask these questions because I beleive, correct me if I'm wrong, that the 512MB stick of RAM is the same physical size as the 256MB stick of RAM and that the only difference is the amount of RAM available on each stick. Where does the problem exsist, in the BIOS, the chip set, the processor, or a combination of these. I'm sure it would be helpful to know the motherboard brand name and the chip set modle number but I'm not sure how to find these out without disassembling my laptop. I can tell you that I bought it in 2001 if that helps at all. I have not actually tried to install 1GB of RAM I've just been told that it won't work and I don't want to spend the money on RAM that won't work. I ask these questions because my curiosity has been peaked and I really want to understand the reason that it won't work, and I would also like to try to change things to allow 1GB of RAM to work. Thanks for any help you can give me.