what kind of ddr i need to purchase for my hp 503n pavilion?

Answer 1

Your computer uses PC2100 DDR RAM, and can hold a maximum of 2GB, and has two RAM slots. While the RAM will only run at a maximum speed of PC2100, you can install DDR RAM of a higher speed in it if that type happens to be cheaper (which it sometimes is).

Answer 2

what you need is pc2100 ddr also known as 266mhz, ur pc comes with 256mb i suggest getting a 1gb or a 512mb