need help with ram for laptops

my friend and I want to upgrade our laptops with memory. We both want the maximum they will hold. My friend has a dell inspiron 2600. I have a sony viao pcg-grv550. We were hoping we could get 1 gb sticks, but according to dell his will only take 1 512 gb stick. we don't know what motherboards are in our laptops. any info is well appreciated.

Its hard to understand what they mean, they either mean that the laptop only supports 512MB, or each slot only supports 512MB. In either case, you cant buy a 1GB stick.

the dell site said there is only one slot, so I guess 512 is the most it can handle. thanks for the info.

i doubt there is only one slot...

alright i take that back...it says the 2600 takes 133mhz...couldnt find how much, but i think 512 is probably going to be the max. couldnt find anything on the motheboard, but if you want to see for yourself just flip the lappy upside down and youll see a rectangular piece, maybe two or three screws...pop it off, and youll see how many slots there are. it might even say "memory" or have an "M" stamped on it...