I have a Compaq Presario 2100 laptop. The RAm is 512Mb (2 x 256 cards). I want to upgrade to 1Gb. Do I have to insert 2 x 512 Mb cards or can I install one 1Gb card?
Remember you are not obliged to buy from that website (although I have done so and had faultless service) - but it does give you all the information you need to buy elsewhere.