I have 3 GB of memory installed in my machine and it is showing that ONLY 2.75 GB is useable. Just wondering what that means. I had my computer in the shop where they replaced my processor, motherboard and installed Windows 7 64 bit. Just wondered why it was showing that. I've never seen that before.
Check what Resource Monitor is reporting for memory.
At the Start Menu type in resource monitor in the search bar at the bottom. Choose Resource Monitor in the Programs category.
On the Memory Tab what is RM reporting for each of the five categories of memory?