Yes it is, but it is known as memory sticks not cards in a desktop pc.I have had vista, firstly in beta form, and when it came out proper. In beta form i was running vista on 512mb memory.Everything was fine, unless i had too many programmes running at the same time. It would in these circumstances state that it was dropping into aero basic mode. Which means less eye-candy. In other words the buttons and highlights were not glowing with a sheen!. When i installed vista proper, i at the same time increased the memory to 1.5 gb. I no longer get these messages. Vista does need a larger memory than xp to run unheeded. Make sure you have enough empty memory slots before you buy. Try to buy a quality name like Crucial, Kingston, or OCZ, if you can afford to, well worth it. Use their web sites for help.
mick
December 2007