only half of memory registering


Nov 3, 2007
i did some searching and i couldent find an answer. i have a hp pavilion zt1000 notebook with a 1.2 ghz celeron and 256 mb of ram, according to the model number and cpu-z. however, dxdiag is only registering it as 128 mb, and i do not have a shared video card (its an s3 twister w/16mb of memory) anyway, i opened up the memory compartment underneath thinking to remove the memory module and check it out but there is only one slot that is accessible, and its empty. im wondering if hp somehow put non-removable memory in it. i came upon this because i realized that the laptop was running much slower, but it had not been used in over a year. also, if anyone can help me out i would also like to install a faster mobile celeron in it, and im also wondering if the motherboard accepts petium 4-m because this model series used 6 different cpu's at one point, but im not sure if hp used the same mb throughout. i know this isnt the right section for that question but im just curious. thanks
sometimes for laptops the ram is (or some of it) a part of the main board its self and cannot be disabled or removed, other times is located somewhere else like under the keyboard etc, and as for upgrading the laptop - its not worth the time or money, and i dont think it could handle or cool a pentium 4 m, it might actually be an older P3 based celeron rather then a Pentium M based celeron.