Hi, I have a compaq presario 3015ca. for specifications The model was shipped with 512MB/PC266 (2-DIMM) upgradable up to 1024 (2 X 512 MB DIMM). Now this is the question. How do i choose the right ram? I understand that laptop ram is incompatible with desktop. (why?) So I assume there would be laptop ram! is there? For example a local shop has a huge selection of different ram speeds and types. Which should i choose? Are all the speeds compatable with the system. So if my system was shipped with pc266 can I upgrade to 333Mhz? And what is 144pin ram? etc etc. Since there have been many threads on the issue of RAM are there any helpful website which you could suggest. (My google search came up with more confusion than solutions). Cheers Biggusignoramus any help with be appreciated.