I've a latitude d620 w/2 memory cards slots 1has 1GB but the other I install the memory it does not work why?

I have two of then and they have the same problem they only read 1 memory even when I install the two memories on each slot....

I've a latitude d620 w/2 memory cards slots 1has 1GB but the other I install the memory it does not work why?
Many motherboards are tenacious when it comes to memory. First, it is usually best to have dual channel RAM. Secondly, it is best to have the same brand. Third, they should have the same speed (if you have DDR 800 and DDR 667 they 800 will default to the lower speeds) in most cases.





We need to know more about the memory.