Took special versions of the 256MB sticks. You usually won't find them in retail shops but order them from Crucial.com. I've written the technical reasons why a few dozen times so I'll not duplicate that anymore.
I have an older model Hp Pavillion XG833 that i've passed down to my nephew. It has been upgraded to XP and I have tried time and again to get it to accept (2) sticks of 256MB SDRAM however, it will only take a comdination maximum of 384 MB. The system specs. max is 512 MB. Can anyone instruct me as to how I can get the system to accept the maximum.