I don't think you really understood my question. Lets say i have Win XP with 1gig of RAM, two sticks of 512MB. 2 sticks of 512MB = 1GIG of RAM. Now, if your system doesnt go over 512MB which in this example equals only 1 stick of RAM being used, because it didn't go over 512MB. Now if the RAM usage goes over 512MB, the OS is now forced to use the other stick becaue it went over 512MB so now 2 sticks are being used...

So the main question, since the OS is not using more than 512MB of RAM which in this example 512MB is one stick, and that leaves one stick of 512MB that is unused. So since the OS is not using more than 512MB, is the other stick not being used??? Or does it somehow share the memory to 2 sticks, lets say 200MB are being used by the OS, that would mean 100MB on each RAM stick.

If the memory is not shard by the 2 sticks and the memory does no exceed 512MB (1 stick) is the other memory stick going to waste??????
I hope that was clear enough...