My PC has 2 Memory slots and I have Memory Cards in each, I am starting to run out of Computer Memory, so if I buy a new card that has increased Memory and remove 1 of the 2 Cards to replace it, am I going to lose things off of my Computer?
If it's a dual-channel memory controller on your motherboard then you'll have to replace both sticks. I doubt it is since it's such an old motherboard though.
Do you happen to know which motherboard you have?
I have no clue, all I know was that it came with 256 in the 1 slot and had an expansion slot to which I added another 256 card to a couple years after I bought the Computer. There was something odd that happened though as the computer did not account for the new card in the expansion slot, I had to switch the 1 that came with the computer to the expansion slot and the new 1 in the original spot in order for the computer to realize it.
Easiest way to do it in my opinion is to wirte down the PCXXXX number and buy what ever you need. This number indicates the MHZ of the ram, most likely it will be DDR PC2700 which is 333MHZ. Buy 512 for 45 bucks or a gig for about a hundred and you will be all set.
The Crucial site will give you some specs/info on your Pavillion 524. You can shop around after deciding what you want.
http://www.crucial.com/store/listparts.aspx?model=Pavilion+524w