Everest Home Edition reports that I'm using 272MB of RAM, but when I add up the memory usage from the processes listed in WIndows Task Manager, it only adds up to about 97MB. What's using the rest of the RAM?
Funny you should ask this; I ran Everest on a new notebook recently and it reported a similar figure - about half of the 512MB and the graphics card has its own dedicated RAM. I just took it at its word, though did think that it was a little high, and didn't bother to check Task Manager.
I'm not sure whether memory usage would be entirely accounted for in Task Manager anyway; checking in the performance logs would be better - you can create your own memory monitor from Performance Logs and Alerts in Administrative Tools. I can't remember how to do this but if I can find the instructions I'll post a link for you.