Sorry, I put the wrong model number in the question it should be the Sony VAIO VGC-RT100Y. On the Crucial site it says that there are 2 slots with a max capacity of 8 gb memory but then below that it says it is filled with 4 gb (2 X 2) not to exceed manufacturers specificaations. Which it implies is only a total of 4 gb memory. Which is correct? Can these modules be safely used to upgrade my Sony VGC-RT100Y computer without damaging it?
I would highly recommend contacting the manufacturer to verify. After checking the Crucial Adviser for your model, it would appear that upgrading past the the 4GB installed on your unit is not advised (Crucial suggests a 4GB kit as the largest they offer for your model).