Janet, >First, I would like to thank everyone who tried to help me understand the >difference between the different types of memory on a computer's system. It >is now much clearer to me what I am dealing with here. > > I still would like to get an answer to the question I asked earlier, >though, if someone wouldn't mind. The question is: I bought and installed a >second memory card for my computer a year ago. This summer the system >crashed. The people in the shop reformatted and installed Windows XP home >edition. Does my computer automatically "read" both the old memory card >that originally came installed as well as the new one? Is it possible that >I am only getting use out of one of the memory cards? Windows will read all available RAM installed on the computer. It is possible that one card couldn't be read if it was defective. To see how much RAM is installed, go to Start > right click on My Computer. Select Properties. On the general tab, it will state how much is installed. Hope this answers your question! Art